Journal articles: 'Types of lasers'

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Nalcaci, Ruhi, and Serpil Cokakoglu. "Lasers in orthodontics." European Journal of Dentistry 07, S 01 (September 2013): S119—S125. http://dx.doi.org/10.4103/1305-7456.119089.

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ABSTRACTMany types of dental lasers are currently available that can be efficiently used for soft and hard tissue applications in the field of orthodontics. For achieving the desired effects in the target tissue, knowledge of laser characteristics such as power, wavelength and timing, is necessary. Laser therapy is advantageous because it often avoids bleeding, can be pain free, is non-invasive and is relatively quick. The high cost is its primary disadvantage. It is very important to take the necessary precautions to prevent possible tissue damage when using laser dental systems. Here, we reviewed the main types and characteristics of laser systems used in dental practice and discuss the applications of lasers in orthodontics, harmful effects and laser system safety.

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Mote, Nilesh, N. G. Toshniwal, Shubhangi Mani, Ashwini Nalkar, and Vishal Dhanjani. "Lasers in Orthodontics – A Review." Orthodontic Journal of Nepal 10, no. 3 (December 31, 2020): 62–65. http://dx.doi.org/10.3126/ojn.v10i3.35498.

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Introduction: In past few years, there is huge improvement in orthodontics. Different innovation in orthodontics made the procedure easier and less time consuming. Application of laser is one of them. Many types of dental lasers are currently available that can be efficiently used for soft and hard tissue applications in the field of orthodontics. Two types of lasers are there. One is hard tissue laser, and another is soft tissue laser. Laser therapy is advantageous because it often avoids bleeding, can be pain free, is non‑invasive and is relatively quick. The high cost is its primary disadvantage. The purpose of this article is to provide an overview regarding safe and proper use of soft-tissue lasers in orthodontics

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Roux, P. "Die gebruik van lasers in geneeskunde." Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie 13, no. 1 (July 9, 1994): 25–28. http://dx.doi.org/10.4102/satnt.v13i1.578.

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The acronym laser stands for “light amplification by stimulated emission of radiation”. The basic principles by which light energy from a laser is generated is discussed briefly. The different types of lasers are mentioned. The diagnostic and therapeutic uses of lasers in medicine are discussed in greater detail.

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Lisiecki, A. "Comparison of Titanium Metal Matrix Composite Surface Layers Produced During Laser Gas Nitriding of Ti6Al4V Alloy by Different Types of Lasers." Archives of Metallurgy and Materials 61, no. 4 (December 1, 2016): 1777–84. http://dx.doi.org/10.1515/amm-2016-0287.

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Abstract The article presents the results of a comparative study of the nitriding process of titanium alloy substrate using two lasers with different characteristics of laser beams. One of the applied lasers was a high power diode laser emitting at a dominant wavelength of 808 nm, with a rectangular laser beam spot, and multimode energy distribution across the spot. The second laser was a solid state Yb:YAG disk laser emitting at a wavelength of 1.03 μm, with a circular beam spot, characterized by near Gaussian energy distribution across the spot. In a case of both lasers single stringer beads with a similar width and at similar energy input were produced. As a result of melting of the substrate with a laser beam in a pure gaseous nitrogen atmosphere composite surface layers with in situ precipitated titanium nitrides embedded in the metallic matrix of titanium alloy were produced, in both cases. However, the surface topography and structure is different for the surface layers produce by different lasers at the same processing parameters and width of laser beams.

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Wertlen, L. "Lasers in Medicine." Acupuncture in Medicine 10, no. 1 (May 1992): 23–24. http://dx.doi.org/10.1136/aim.10.1.23.

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Lasers now have a wide variety of medical applications, ranging from the dissolution of coronary artery thrombus to the repair of a detatched retina. The main types of laser in medicine are surgical, photocoagulator, photoradiation therapy, and cold lasers which are used by acupuncturists. Cold lasers act directly on cells to improve healing and reduce inflammation. They are also used as an effective substitute for needling or electrical stimulation.

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Jokanovic, Vukoman, Dijana Trisic, and Marija Zivkovic. "Review of lasers application in dentistry." Serbian Dental Journal 67, no. 1 (2020): 36–49. http://dx.doi.org/10.2298/sgs2001036j.

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In this paper the mechanism of stimulated emission is described as the fundamental of laser technology. The types of lasers from the aspect of their operation are also given. The particular attention is paid to dental lasers and their effect on healing processes in bone, dentin, enamel etc.

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Priya, NK, NK Sowmya, and Ashiwini Ramakrishna. "Lasers in dentistry - Thinking ahead…" CODS Journal of Dentistry 6, no. 2 (2014): 102–7. http://dx.doi.org/10.5005/cods-6-2-102.

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Abstract Laser technology was introduced in the field of dentistry with a novel idea of overcoming few problems or drawbacks posed by the conventional methods. Theodore Maiman in 1960 introduced the first solid state ruby laser. Since then lasers have gained its popularity in different fields of dentistry. Laser in dentistry is now in vogue and now becoming a part of the dentist's armamentarium. This article gives an insight to the basics of laser physics, types of laser, mechanism of action, their interactions with biologic tissues and their advantage and disadvantage. How to cite this article Priya NK, Sowmya NK, Ashwini R, Madhushankari GS, Lasers in Dentistry - Thinking ahead… CODS J Dent 2014;6;102-107

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Srivastava, Rishi, Waisum Cho, and Neil Fergie. "The Use of Lasers in Stapes Surgery." Ear, Nose & Throat Journal 100, no. 1_suppl (June 30, 2020): 73S—76S. http://dx.doi.org/10.1177/0145561320937828.

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Objectives: Otosclerosis is a disease process that usually starts around the oval window, causing fixation of the stapes, resulting in conductive hearing loss. Treatment of the conductive hearing loss caused by otosclerosis consists of either rehabilitation with hearing aids or performing surgery. Given the risks of hearing impairment and vertigo associated with the surgery, there has been a desire to advance the practice to minimize the complications. The so-called “non-contact” or “no touch” techniques with the use of various lasers are in current practice. This review article will cover the surgical aspects, the theory behind laser and the various types used in stapes surgery. It will also review the evidence of laser versus conventional stapes surgery and the comparison of different laser types. Methods: A literature search up to December 2019 was performed using Pubmed and a nonsystematic review of appropriate articles was undertaken. Keywords used were stapes, surgery, laser, stapedectomy, and stapedotomy. Results: Overall, there is no evidence to say laser fenestration is better than conventional fenestration techniques; however, with the micro drill, there is an increased risk of footplate fracture and sensorineural hearing loss. There is an increased risk of tinnitus with the laser compared to conventional techniques. Studies have favored the CO2 laser over potassium titanyl phosphate (KTP) and erbium-doped yttrium aluminium garnet (Erbium-YAG) lasers for postoperative closure of the air-bone gap; and KTP laser has less thermal, mechanical, and sound effects compared with the thulium and carbon dioxide (CO2) lasers. There is an increased risk if inner ear complications with the thulium laser. Conclusions: It can be deduced that theoretically and practically, the thulium laser is less safe compared to the KTP and CO2 lasers. The choice of laser used depends on the surgeon’s preference, as well as availability, cost, side effects profile, as well as ease of use.

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Apollonov, V. V., A. I. Artemyev, M. V. Fedorov, J. K. McIver, and E. A. Shapiro. "Gas–plasma and superlattice free-electron lasers exploiting a medium with periodically modulated refractive index." Laser and Particle Beams 16, no. 2 (June 1998): 267–76. http://dx.doi.org/10.1017/s0263034600011599.

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Free-electron lasers exploiting media with periodically modulated refractive indices are studied. The regime of large modulation is considered, and the conditions of its realization are discussed. Two types of media with periodically modulated refractive indices are analyzed: a gas-plasma medium with a periodically varying degree of ionization and a superlattice-like medium. The gain, saturation field, and efficiency of these free-electron lasers are found. For any given frequency, the gain is optimized with respect to the choice of electron energy, direction of motion, and other parameters. Its relationship with other types of free-electron lasers (e.g., the Cherenkov laser) is discussed.

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Ballagh, R. J., and C. M. Savage. "The Theory of Atom Lasers." Modern Physics Letters B 14, supp01 (September 2000): 153–88. http://dx.doi.org/10.1142/s0217984900001543.

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We review the current theory of atom lasers. A tutorial treatment of second quantisation and the Gross-Pitaevskii equation is presented, and basic concepts of coherence are outlined. The generic types of atom laser models are surveyed and illustrated by specific examples. We conclude with detailed treatments of the mechanisms of gain and output coupling.

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Francesca, F. "Lasers in Urology: Stone disease." Urologia Journal 63, no. 1 (February 1996): 97–99. http://dx.doi.org/10.1177/039156039606300117.

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— Laser devices for endoscopic lithotripsy differ in their technical aspect from those designed for other urological applications. Their main characteristic is represented by the Q switched output to avoid the thermal effect, which is always associated with the continuous wave output of other lasers. The wave length allows the selective absortion of energy by the stone, greatly reducing the risk of tissue damage. At present three types of laser are available for endoscopic lithotripsy: pulsed dye laser (coumarine green); wave length: 504 nm. Pulsed dye laser (rodamine); wave length: 594 nm. Alexandrite laser; wave length: 750 nm. The pros and cons of laser lithotripsy compared to other methods for endoscopic lithotripsy are highlighted.

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Лябин, Николай, Nikolay Lyabin, Мишик Казарян, Mishik Kazaryan, Александр Григорьянц, Aleksandr Grigoryants, Игорь Шиганов, and Igor Shiganov. "Comparative analysis of pulse copper vapour laser parameters fume with known types of technological lasers." Science intensive technologies in mechanical engineering 2, no. 1 (January 31, 2017): 37–48. http://dx.doi.org/10.12737/24211.

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The shown in the work investigations on a comparative analysis of emission parameters of lasers and laser systems on copper vapour (LPM and LSPM) with known technological gas and solid-state lasers have shown that LPM and LSPM with wave lengths of emission in a yellow-green spectrum range – 510.6 and 578.2 nm; pulse nano-second duration – 10…30ns; high frequencies of pulse repetition – 10…20kH and low pulse energy – 0.1…10mJ stay power pulse sources of coherent radiation and according to parameter totality are unique tools for micro-processing. On the basis of the complex of scientific-technical, technological and circuit solutions there is created a new generation with high efficiency, reliability and quality of emission, industrial welded-off active elements on copper vapour of small (1…20W) and average (30…100W) levels of power and on their basis industrial LPM and LSPM for the collection of technological equipment. High coherent emission of this class of lasers with the aid of objective lens is focused in a spot of small dimensions – 10…20µm with the peak power density 109…1012W/cm2 sufficient for the efficient micro-processing of materials.

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Khalkhal, Ensieh, Majid Rezaei-Tavirani, Mohammad Reza Zali, and Zahra Akbari. "The Evaluation of Laser Application in Surgery: A Review Article." Journal of Lasers in Medical Sciences 10, no. 5 (December 1, 2019): S104—S111. http://dx.doi.org/10.15171/jlms.2019.s18.

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There are several types of surgeries which use lasers in the operating room. Surgeons use lasers in general surgery or surgical specialties to cut, coagulate, and remove tissue. In modern medicine, the application of laser therapy is an attractive subject due to its minimal invasive effect. Today lasers are widely used in the treatment and diagnosis of many diseases such as various cancers, lithotripsy, ophthalmology, as well as dermatology and beauty procedures. Depending on the type of lasers, the wavelength and the delivery system, most lasers have replaced conventional surgical instruments for better wound healing results. Over time, by using many different tools and devices, new lasers have been created; as a result, they are used in a wide range of medical special cases. In this review, laser applications in surgery and its beneficial effects compared to previous surgeries with the aim of providing appropriate therapeutic and non-invasive solutions with minimal side effects after surgery are investigated.

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Sun, Tianyu, Lei Qiao, and Mingjun Xia. "Effective Failure Analysis for Packaged Semiconductor Lasers with a Simple Sample Preparation and Home-Made PEM System." Photonics 8, no. 6 (May 24, 2021): 184. http://dx.doi.org/10.3390/photonics8060184.

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As the application requirements of semiconductor lasers continue to increase, severe challenges are brought to the reliability of semiconductor lasers. In order to promote the study of laser failure, this paper proposes an effective failure analysis method for packaged semiconductor lasers with a simple sample preparation and home-made photon emission microscopy (PEM) system. The new simple sample preparation process for failure analysis is presented and the necessary polishing fixture is designed so that sample can be obtained without expensive and complex micro-/nano-processing. Two types of home-made PEM experimental systems were established for observing the failure from the front facet and active region of semiconductor lasers. Experimental results showed that, with the proposed sample preparation flow, the home-made PEM experimental system effectively observed the leakage defects from the front facet and dark spot defects (DSDs) in the active region of semiconductor lasers. The method can help researchers and laser manufactures to perform effective failure analysis of packaged semiconductor lasers.

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Ohsugi, Yujin, Hiromi Niimi, Tsuyoshi Shimohira, Masahiro Hatasa, Sayaka Katagiri, Akira Aoki, and Takanori Iwata. "In Vitro Cytological Responses against Laser Photobiomodulation for Periodontal Regeneration." International Journal of Molecular Sciences 21, no. 23 (November 26, 2020): 9002. http://dx.doi.org/10.3390/ijms21239002.

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Periodontal disease is a chronic inflammatory disease caused by periodontal bacteria. Recently, periodontal phototherapy, treatment using various types of lasers, has attracted attention. Photobiomodulation, the biological effect of low-power laser irradiation, has been widely studied. Although many types of lasers are applied in periodontal phototherapy, molecular biological effects of laser irradiation on cells in periodontal tissues are unclear. Here, we have summarized the molecular biological effects of diode, Nd:YAG, Er:YAG, Er,Cr:YSGG, and CO2 lasers irradiation on cells in periodontal tissues. Photobiomodulation by laser irradiation enhanced cell proliferation and calcification in osteoblasts with altering gene expression. Positive effects were observed in fibroblasts on the proliferation, migration, and secretion of chemokines/cytokines. Laser irradiation suppressed gene expression related to inflammation in osteoblasts, fibroblasts, human periodontal ligament cells (hPDLCs), and endothelial cells. Furthermore, recent studies have revealed that laser irradiation affects cell differentiation in hPDLCs and stem cells. Additionally, some studies have also investigated the effects of laser irradiation on endothelial cells, cementoblasts, epithelial cells, osteoclasts, and osteocytes. The appropriate irradiation power was different for each laser apparatus and targeted cells. Thus, through this review, we tried to shed light on basic research that would ultimately lead to clinical application of periodontal phototherapy in the future.

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Labunet, Anca, Andreea Kui, and Sorina Sava. "Laser Use in Creating Orthodontic Adhesion to Ceramic Surfaces." Applied Sciences 11, no. 6 (March 11, 2021): 2512. http://dx.doi.org/10.3390/app11062512.

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Orthodontists must sometimes bond attachments to ceramic crowns, by using one of the surface preparations available, such as sandblasting or acid etching with hydrofluoric acid. Research shows that different laser systems may also be used for this purpose. The aim of this review is to determine which laser type and modality of use is the most effective in increasing shear bond strength of brackets bonded to ceramic surfaces. Two independent researchers studied the current literature 1990–2018 and selected original articles focusing on in vitro research on laser use for ceramic surface preparation for bonding metallic or ceramic attachments. Twelve articles have met the criteria and have been thoroughly revised, focusing on 2 fractional, Nd:Yag, Er:Yag, femtosecond and Ti:Sapphire lasers. There is little difference shown by the current studies between ceramic types and information on orthodontic bonding to non-feldspathic ceramics is scarce. Femtosecond laser is a good alternative to classical surface preparation with hydrofluoric acid. Nd:Yag laser is more suitable for surface preparation of ceramics than different types of Er:Yag lasers. Difference in laser power may achieve different results, but the golden standard for lasers use has not been found. Laser usage does not obtain the same results as hydrofluoric acid and cannot, so far, eliminate its application.

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Battle, Eliot F., and Cylburn E. Soden. "The Use of Lasers in Darker Skin Types." Seminars in Cutaneous Medicine and Surgery 28, no. 2 (June 2009): 130–40. http://dx.doi.org/10.1016/j.sder.2009.04.003.

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Mordon, S. "Différents types de lasers, sources de lumières disponibles." EMC - Cosmétologie et dermatologie esthétique 1, no. 1 (January 2006): 1–11. http://dx.doi.org/10.1016/s1283-0143(06)44991-8.

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Otsuji, Taiichi, Akira Satou, Stephane Boubanga Tombet, Alexander A. Dubinov, Vyacheslav V. Popov, Victor Ryzhii, and Michael S. Shur. "Graphene Active Plasmonics for New Types of Terahertz Lasers." International Journal of High Speed Electronics and Systems 23, no. 03n04 (September 2014): 1450016. http://dx.doi.org/10.1142/s0129156414500165.

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This paper reviews recent advances toward new types of terahertz (THz) lasers using active plasmonics in graphene. Optical gain originated from graphene ultrafast nonequilibrium carrier dynamics and phonon properties in the broadband THz frequency range might pave the way for the THz lasers but the challenge is to overcome the strong losses in the THz range. Graphene plasmons, quanta of the collective charge density waves excited by the two-dimensional carriers in graphene, can substantially enhance the light-matter (THz photons-graphene) interaction, leading to a “giant THz gain”. One possible implementation relies on superradiant plasmonic THz lasing in graphene-metal micro-ribbon array structures.

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El, Haj, Han Bani, Israa Al-Sawafta, Ahmad Sedaghat, M. Alshabi, and Shek Rahman. "Thermal analysis of end pumped fiber lasers subjected to jacket fluid cooling." Thermal Science, no. 00 (2019): 311. http://dx.doi.org/10.2298/tsci190407311e.

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End pumped lasers are highly efficient lasers particularly in diode lasers using micro lenses. The common cooling method for end-pumped systems is using water jacket or copper tube surrounding the laser rod. In this paper, the temperature distribution within a water jacket and a fiber laser end pumped by a top hat beam is studied analytically. The temperature distribution is obtained by considering the radial heat convection with fully developed laminar flow neglecting the axial heat conduction. The effect of laser dimensions and the Brinkman number on the temperature distribution are presented. The results indicate that the temperature distribution is strongly dependent on the Brinkman number. The results are presented in dimensionless form so that they can be applied to any end-pumped laser rod and fluid types. The main output of this work is that it is better for cooling purposes to have low Br values.

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Tran, Chieu D., and Ricardo J. Furlan. "Indirect Amplitude Stabilization of a Tunable Laser through Control of the Intensity of a Pump Laser by an Electro-Optic Modulator." Applied Spectroscopy 47, no. 2 (February 1993): 235–38. http://dx.doi.org/10.1366/0003702934048172.

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A novel method has been developed to stabilize the intensity of a tunable laser. In this method, the tunable laser is amplitude-stabilized indirectly by controlling the intensity of the pump laser through an electro-optic modulator placed between the pump and the tunable lasers. A small portion of the tunable laser beam was split into a reference photodiode to provide a reference signal for the feedback driver to drive the Pockels cell. Any fluctuation in the intensity of the tunable laser is compensated for by varying the intensity of the pump laser through the feedback driven Pockels cell. Results obtained on the Ti-sapphire laser pumped by an ion laser demonstrate that up to 100 × reduction in the laser noise level can be accomplished by use of this method. Furthermore, with this method, it is possible to adjust the intensity of the laser to be exactly equal for different wavelengths, and to maintain this level for as long as the stabilization is activated. Applications of this method for different types of tunable lasers, including dye and F-center lasers, are discussed.

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Sołtysiak, Robert, Piotr Wasilewski, Agnieszka Sołtysiak, Adam Troszyński, and Paweł Maćkowiak. "The Analysis of Fiber and CO2 Laser Cutting Accuracy." MATEC Web of Conferences 290 (2019): 03016. http://dx.doi.org/10.1051/matecconf/201929003016.

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The aim of the conducted research was to compare the functional properties and the cutting accuracy of items produced using Fiber lasers in comparison with CO2 lasers. The object of 6 mm thick sheet plates made of S235JR steel cut with the two different laser types were analyzed. The tests covered dimensional accuracy (in accordance with the PN EN 22768-fH standard) and the surface after cutting (in accordance with the PN-EN ISO 9013: 2017-04). The results of the analysis have demonstrated that for the same welding linear energy, more accurate cutting surface is obtained using Fiber laser cutting.

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Dzhemileva, T., Slav Dimitrov, V. Dogandzhiyska, Ts Georgieva, V. Kalchinov, V. Mantareva, I. Angelov, and V. Kussovski. "High-energy lasers: principles, types, indications in periodontial practices." Scripta Scientifica Medica 43, no. 2 (December 20, 2011): 87. http://dx.doi.org/10.14748/ssm.v43i2.390.

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Nazemisalman, Bahareh, Mahya Farsadeghi, and Mehdi Sokhansanj. "Types of Lasers and Their Applications in Pediatric Dentistry." Journal of lasers in medical sciences 6, no. 3 (June 28, 2015): 96–101. http://dx.doi.org/10.15171/jlms.2015.01.

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Wu, Qi, and Jun Wang. "Development in Laser Polishing of Polycrystalline Diamond Tools." Advanced Materials Research 135 (October 2010): 1–6. http://dx.doi.org/10.4028/www.scientific.net/amr.135.1.

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Laser polishing is a surface finishing technology for polycrystalline diamond (PCD) tools by removing uneven diamond particles from the diamond film through graphitization, melting and sublimation. While various types of lasers are used for the polishing of PCD tools, pulsed excimer and Nd: YAG lasers are among the most commonly used ones. The current development in laser polishing of PCD tools is reviewed. The reported experimental and modelling studies to improve the process performance are discussed. It reveals that there is a severe dearth of understanding of the process and the associated models for the efficient and effective use of the technology. The direction of future research in laser polishing is finally discussed.

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Ali Al - Saidi, Imad Al Deen Hussein, Majdi Faisal Majeed, and Ikram Kamal Jasim. "EFFECTS OF LASER IRRADIATION ON NORMAL AND ANEMIC HUMAN BLOOD." International Journal of Research -GRANTHAALAYAH 8, no. 8 (September 1, 2020): 256–61. http://dx.doi.org/10.29121/granthaalayah.v8.i8.2020.862.

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The effects of laser irradiation on the whole human blood were studied. The blood samples were taken from healthy donors with normal blood and donors with anemic blood. The blood samples were exposed to laser radiation. Two lasers of the same types, continuous wave (CW) diode pumped solid-state lasers (DPSSL’ s) were used to irradiate the blood samples. One of these laser has a wavelength 532 nm (green laser beam), while the other laser has a wavelength 671 nm (red laser beam). The output power of the two lasers can be varied over the range 0 - 100 mW. In the present study, the output power was fixed at 20 mW for both lasers. The blood samples were exposed to different irradiation times, 5, 15, and 30 min. Significant changes in the optical parameters of the irradiated blood samples were observed in comparison with that of the un-irradiated blood samples (the control samples). These optical parameters were determined from the measured absorbance spectra of the un-irradiated and irradiated samples. The absorbance spectra were measured using a UV-Visible double-beam spectrophotometer operating over the wavelength range 190 - 1100 nm. The results of the present study revealed that the laser irradiation can produce considerable effects on the human blood samples, suggesting the suitability of the laser beam irradiation for the biological and medical applications.

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Ilchyshyn, I. P., and E. A. Tikhonov. "How Laser Physics Brought Optics to the World of Photonic Crystals." Ukrainian Journal of Physics 65, no. 4 (April 17, 2020): 327. http://dx.doi.org/10.15407/ujpe65.4.327.

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A brief review of authors’ research is presented. An emphasis is made on the photon localization in the helical structure of a chiral liquid crystal (CLC), which was first experimentally registered by the authors. An analysis of the spectral and lasing characteristics of distributed feedback (DF) lasers based on natural CLCs (type 1) and on chiral nematics (type 2) led to a conclusion that the model of photonic crystal is suitable to describe the lasing mechanism in type-2 CLC lasers, but not in type-1 ones. This conclusion is evidenced by the absence of lasing bands at the opposite edges of the selective reflection (SR) band; at the same time, the lasing line is located at its center. It is shown that if the SR band of the CLC overlaps the maximum of the laser dye fluorescence band, the lasing line coincides with the SR band center to an error of ±1 nm. If the layer thickness in the CLC lasers of both types does not exceed 50 мm, when a high-quality planar texture is retained and a low generation threshold is achieved, a significant difference between their optical characteristics takes place. Namely, the SR spectrum for a type-1 CLC laser is approximately described by a Lorentzian profile, whereas the contour of the SR spectrum for a type-2 CLC laser has a profile characteristic of the transmittance through multilayer dielectric mirrors. The origins of the differences between the optical and laser characteristics of the CLC lasers of both types have been analyzed from the viewpoint of two lasing models: DF and photonic-crystal ones.

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Evtushenko, G. S., A. V. Klimkin, M. E. Levitsky, V. F. Tarasenko, and M. V. Trigub. "AMPL INTERNATIONAL CONFERENCE (1992–2019) AND ITS ROLEIN THE DEVELOPMENT OF PHYSICS AND TECHNOLOGY OF PULSEDLASERS, AS WELL AS THEIR APPLICATIONS." Innovatics and Expert Examination, no. 1(29) (July 1, 2020): 103–10. http://dx.doi.org/10.35264/1996-2274-2020-1-103-110.

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From September 15 up to September 20, 2019, the regular, 14th International Conference on Pulsed Lasers and Laser Applications – AMPL (abbreviation from the English name Atomic and Molecular Pulsed Lasers) was held in Tomsk. AMPL Conference (https://symp.iao.ru/ru/ampl), which is a periodic scientific event and takes place every two years in the city of Tomsk. The first conference was held in 1992, and all subsequent ones since 1995 took place on odd years. The AMPL conference is traditionally held in mid-September. Conference topics – fundamental issues of laser physics, physicochemical processes in active laser media, new types of lasers and laser systems, the use of lasers in science, technology, medicine, other fields of activity, problems of bringing laser devices and technologies to the market, as well as fundamental and applied issues on the creation and use of spontaneous radiation sources (excilamps). Along with Russian scientists, specialists, graduate students and students, representatives of near and far abroad regularly participate in the conference. The article provides a brief overview of past conferences, notes how the conference topics were expanded and modified in response to the challenges of gaining new knowledge in the field of photonics, as well as the needs of the laser equipment and technology market. An analysis of the current state of fundamental and applied research is given, and trends in the development of laser technologies are discussed.

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Turconi, M., M. Giudici, and S. Barland. "Response of laser-localized structures to external perturbations in coupled semiconductor microcavities." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 372, no. 2027 (October 28, 2014): 20140004. http://dx.doi.org/10.1098/rsta.2014.0004.

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Laser-localized structures have been observed in several experiments based on broad-area semiconductor lasers. They appear as bounded regions of laser light emission which can exist independently of each other and are expected to be commuted via external optical perturbations. In this work, we perform a statistical analysis of time-resolved commutation experiments in a system of coupled lasers and show the role of wavelength, polarization and pulse energy in the switching process. Furthermore, we also analyse the response of the system outside of the stability region of laser-localized states in search of an excitable response. We observe not only a threshold separating two types of responses, but also a strong variability in the system's trajectory when returning to the initial stable fixed point.

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Lisiecki, A. "Welding of Thermomechanically Rolled Fine-Grain Steel by Different Types of Lasers/ Spawanie Stali Drobnoziarnistej Walcowanej Termomechanicznie Laserami Różnego Typu." Archives of Metallurgy and Materials 59, no. 4 (December 1, 2014): 1625–31. http://dx.doi.org/10.2478/amm-2014-0276.

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Abstract The autogenous laser welding of 2.5 mm thick butt joints of thermomechanically rolled fine-grain steel grade S420MC was investigated. Butt joints were laser welded by the Yb:YAG Disk laser, emitted a circular laser beam with spot diameter of 200 μm at 1.03 μm wavelength, and also by the high power direct diode laser, emitted a rectangular beam with dimension of 1.8x6.8 mm at 808 nm wavelength. Different welding modes were identified for the lasers applied. The conduction welding mode was observed in whole of the diode laser welding parameters. While high quality joints, without any internal defects and characterized with satisfactory mechanical performance were produced in a wide range of parameters. The butt joints produced by Disk laser were welded at keyhole mode. In this case a slight tendency to weld porosity was found.

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Anghel, Dan Alexandru, Andreea Rodica Sterian, and Paul E. Sterian. "Modeling Quantum Well Lasers." Mathematical Problems in Engineering 2012 (2012): 1–11. http://dx.doi.org/10.1155/2012/736529.

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In semiconductor laser modeling, a good mathematical model gives near-reality results. Three methods of modeling solutions from the rate equations are presented and analyzed. A method based on the rate equations modeled in Simulink to describe quantum well lasers was presented. For different signal types like step function, saw tooth and sinus used as input, a good response of the used equations is obtained. Circuit model resulting from one of the rate equations models is presented and simulated in SPICE. Results show a good modeling behavior. Numerical simulation in MathCad gives satisfactory results for the study of the transitory and dynamic operation at small level of the injection current. The obtained numerical results show the specific limits of each model, according to theoretical analysis. Based on these results, software can be built that integrates circuit simulation and other modeling methods for quantum well lasers to have a tool that model and analysis these devices from all points of view.

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ROS, D., G. JAMELOT, A. CARILLON, P. JAEGLÉ, A. KLISNICK, P. ZEITOUN, B. RUS, et al. "State of the development of X-ray lasers and applications at LSAI." Laser and Particle Beams 20, no. 1 (January 2002): 23–30. http://dx.doi.org/10.1017/s0263034602201032.

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Obtaining an X-ray laser emission from plasmas, created and driven by an intense IR laser, has been pursued at the Laboratoire de Spectroscopie Atomique et Ionique (LSAI) for several years. At present, we operate various types of X-ray lasers driven by IR laser pulses of different durations (600 ps, 100 ps, and 600 ps/1 ps). A review of different techniques used at the LSAI to produce a strongly amplified emission using the collisional excitation pumping is presented. In the second part of this paper, to illustrate the potential of the X-ray lasers for applications, we present the main results obtained with an X-ray laser emitting at 21.2 nm in a study of surface defects of a niobium cathode, induced by strong electrical fields. We also describe a novel imaging interferometry device using an X-ray laser as a source and designed as a tool for high-resolution diagnostic of dense plasmas.

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Bernatskyi, Artemii, and Vladyslav Khaskin. "The history of the creation of lasers and analysis of the impact of their application in the material processing on the development of certain industries." History of science and technology 11, no. 1 (June 26, 2021): 125–49. http://dx.doi.org/10.32703/2415-7422-2021-11-1-125-149.

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The paper is devoted to the analysis of the history of the creation of the laser as one of the greatest technical inventions of the 20th century. This paper focuses on establishing a relation between the periodization of the stages of creation and implementation of certain types of lasers, with their influence on the invention of certain types of equipment and industrial technologies for processing the materials, the development of certain branches of the economy, and scientific-technological progress as a whole. In preparing the paper, the generally accepted methods, which are widely used in the preparation of historical research works, have been applied: the historical method – for the study and interpretation of the texts of primary sources and the search for other evidence used for research, as well as for the presentation of historical events associated with the development of laser technology; the historical-genetic method – for studying the genesis of specific historical phenomena and analyzing the causality of changes in the development of laser technology; the historical-critical method – for displaying cause-and-effect relationships, reconstructing events that influenced the development of laser technology; the method of historical periodization. The variety of different possible options for the use of lasers did not allow placing all the collected materials within the framework of one paper, and therefore, the authors have decided to dwell on the facts, which, in the opinion of the paper’s authors, are the most interesting, significant, poorly studied, and little known. The paper discusses the stages of: invention of the first laser; creation of the first commercial lasers; development of the first applications of lasers in industrial technologies for processing the materials. Special attention is paid to the “patent wars” that accompanied different stages of the creation of lasers. A comparative analysis of the market development for laser technology from the stage of creation to the present has been carried out. It has been shown that the modern market for laser technology continues to develop actively, as evidenced by the continued stable growth of laser sales over the past 10 years. This indicates that the demand for laser technology is inextricably linked with the development of high technology production and scientific-technological progress. The analysis has shown that recently, the trends in the use of laser technology have changed; in particular, their industrial and medical applications are decreasing, while there is an increase in their use in the fields of sensor production and communication.

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KO, JING-YUAN, TAKAYUKI OHTOMO, KAZUTAKA ABE, and KENJU OTSUKA. "NONLINEAR DYNAMICS AND APPLICATION OF LASER-DIODE-PUMPED MICROCHIP SOLID-STATE LASERS WITH OPTICAL FEEDBACK." International Journal of Modern Physics B 15, no. 26 (October 20, 2001): 3369–95. http://dx.doi.org/10.1142/s0217979201007282.

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This paper reviews our recent research on nonlinear dynamics of microchip solid-state lasers subjected to delayed optical feedback. Instabilities in two types of physical systems including multimode lasers with feedback and lasers with frequency-shifted feedback are discussed. Applications of microchip lasers with feedback to shot-noise-limited self-mixing optical sensing and imaging are summarized.

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Alfano, Scott, W. B. Wang, and S. K. Gayen. "Lasers in Cancer Detection and Diagnosis Research: Enabling Characteristics with Illustrative Examples." Technology in Cancer Research & Treatment 4, no. 6 (December 2005): 663–73. http://dx.doi.org/10.1177/153303460500400611.

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The salient properties of laser light and the way light interacts with biological tissues and molecular constituents of tissues offer possibilities for detection and diagnosis of cancer. In particular, the wavelength selectivity of tunable lasers, narrow bandwidth around the selected wavelength, and spectral brightness enable probing of key molecular constituents of tissues, and endow laser-based techniques with much desired diagnostic potential. This article presents an overview of some recent developments in optical imaging and optical biopsy of different types of cancers, and illustrates the diagnostic role of the color of light.

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Azma, Ehsan, and Melika Razaghi. "Laser Treatment of Oral and Maxillofacial Hemangioma." Journal of Lasers in Medical Sciences 9, no. 4 (September 17, 2018): 228–32. http://dx.doi.org/10.15171/jlms.2018.41.

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Hemangioma is a congenital vascular soft tissue tumor, defined as a vascular lesion present in the newborn, with a progressive developmental pattern related to age. It has a progressive and regressive periodic growth mode, in comparison with arteriovenous malformation (AVM). Although there are many treatment approaches for curing this lesion such as; surgery, cryotherapy, sclerosant agents, laser therapy has more advantages in comparison to the other methods. Such as, hemostasis and clean operating field, decreased amount of pain and edema. There are many types of lasers manufactured that could be used for therapeutic purposes. This article focuses on different types of laser applications in the treatment of these lesions.

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Rezazadeh, Fahimeh, Paria Dehghanian, and Dana Jafarpour. "Laser Effects on the Prevention and Treatment of Dentinal Hypersensitivity: A Systematic Review." Journal of Lasers in Medical Sciences 10, no. 1 (December 15, 2018): 1–11. http://dx.doi.org/10.15171/jlms.2019.01.

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Introduction: Dentinal hypersensitivity (DH) is an acute intensive tooth pain which can lead to dental annoyances during eating and drinking. Stimulating exposed dentinal tubules by either kind of thermal, tactile, chemical and/or osmotic stimuli is believed to be the cause of this pain. It is hypothesized that dentinal tubules’ orifice occlusion (DOO) can help relieve such dental irritations. Thus, this systematic review was conducted to evaluate the effectiveness of laser application as a prevention and treatment modality on DH reduction. Methods: Electronic databases (MEDLINE, SCOPUS) were searched among randomized clinical trials from January 2007 to December 2016. The extraction of data and quality assessments were carried out by different independent observers. Results: A total of 499 items were found of which3 9 relevant articles were extracted. The profound findings proved lasers’ effectiveness as a treatment of DH. Although some of the researches reported no significant difference between laser and other desensitizing agents, most of the studies suggested that better results (both rapid and long-lasting) were obtained in combined modalities. Furthermore, the preventive role of this new technology has been emphasized as well. Nd-YAG (neodymium-doped yttrium aluminum garnet) and diode lasers reduce DH after bleaching. Lasers can also protect cervical restorations from DH due to tubular occlusion. Moreover, it is suggested to apply lasers in relief of DH following scaling and root planning. Nevertheless, a few researchers dispute its beneficence as a result of placebo effect. Conclusion: The results obtained from several studies in the present review revealed that the application of lasers is effective not only in terms of treatment of DH, but also in the prevention of this intensive tooth pain. Among various types of lasers, the application of Nd:YAG laser has shown the best results in DH treatment.

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Glotov, A. N., Yu V. Golubenko, V. A. Desyatskov, and A. V. Stepanov. "Certain Features of Interaction Between Laser Radiation and Metals." Herald of the Bauman Moscow State Technical University. Series Instrument Engineering, no. 1 (130) (February 2020): 15–32. http://dx.doi.org/10.18698/0236-3933-2020-1-15-32.

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The paper presents experimental investigation results concerning the problem of optimising the efficiency of interaction between laser radiation and metals. We used several types of Nd lasers featuring the desired combination of power, temporal and spatial radiation parameters as sources of the radiation required. To pump these lasers, we employed rectangular pulses at a periodicity eliminating effects characteristic of continuous-wave and pulsed laser operation modes. This limits the laser radiation parameters driving the interaction efficiency functions to strictly those parameters that match the single-pulse laser operation mode. Temporal radiation parameter variation involved measurements in the free-running and high-frequency Q-switching modes as well as adjusting pumping (lasing) pulse durations. Power parameter variation was implemented through altering radiation energy density over the irradiated surface. Spatial structure of the ablative radiation was varied by means of optical radiation transfer facilities and different laser emitters. The experimental investigation results allowed us to establish certain patterns concerning the interaction between laser radiation and metals as a function of radiation parameters listed

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Otsuji, T., S. B. Tombet, A. Satou, M. Ryzhii, and V. Ryzhii. "Terahertz-Wave Generation Using Graphene: Toward New Types of Terahertz Lasers." IEEE Journal of Selected Topics in Quantum Electronics 19, no. 1 (January 2013): 8400209. http://dx.doi.org/10.1109/jstqe.2012.2208734.

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Locquet, A., C. Masoller, P. Mégret, and M. Blondel. "Comparison of two types of synchronization of external-cavity semiconductor lasers." Optics Letters 27, no. 1 (January 1, 2002): 31. http://dx.doi.org/10.1364/ol.27.000031.

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41

Boscolo, Sonia, Sergey V. Sergeyev, Chengbo Mou, Veronika Tsatourian, Sergei Turitsyn, Christophe Finot, Vitaly Mikhailov, Bryan Rabin, and Paul S. Westbrook. "Nonlinear pulse shaping and polarization dynamics in mode-locked fiber lasers." International Journal of Modern Physics B 28, no. 12 (April 7, 2014): 1442011. http://dx.doi.org/10.1142/s0217979214420119.

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We review our recent progress on the study of new nonlinear mechanisms of pulse shaping in passively mode-locked fiber lasers. These include a mode-locking regime featuring pulses with a triangular distribution of the intensity, and spectral compression arising from nonlinear pulse propagation. We also report on our recent experimental studies unveiling new types of vector solitons with processing states of polarization for multi-pulse and tightly bound-state soliton (soliton molecule) operations in a carbon nanotube (CNT) mode-locked fiber laser with anomalous dispersion cavity.

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Dai, Lilong, Zinan Huang, Qianqian Huang, Chang Zhao, Aleksey Rozhin, Sergey Sergeyev, Mohammed Al Araimi, and Chengbo Mou. "Carbon nanotube mode-locked fiber lasers: recent progress and perspectives." Nanophotonics 10, no. 2 (November 24, 2020): 749–75. http://dx.doi.org/10.1515/nanoph-2020-0446.

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AbstractCarbon nanotubes (CNTs) possess remarkable nonlinear optical properties; a particular application is to function as a mode locker used in ultrafast fiber lasers to produce ultrashort optical pulses. Various types of CNT saturable absorbers (SAs) and ultrafast fiber lasers have been demonstrated. In this review, typical fabrication process and development of CNT SAs are discussed and we highlight the recent investigation and progress of state-of-the-art ultrafast fiber lasers covering GHz, bidirectional ultrafast fiber lasers, vectorial mode fiber lasers, comb systems, and mode-locking dynamics. Our perspectives of ultrafast fiber lasers based on CNT SAs are given finally.

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Condor, Daniela, Cristian Culcițchi, Rebecca Blum, Oana Baru, Smaranda Buduru, Andreea Kui, and Ioan Țig. "A Review of CO2 Laser-Mediated Therapy for Oral Mucosal Lesions." Applied Sciences 11, no. 16 (August 23, 2021): 7744. http://dx.doi.org/10.3390/app11167744.

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(1) Background: Several studies investigating the clinical outcomes of potentially premalignant oral epithelial lesions treated with CO2 lasers have been published over the last decades. (2) Methods: A systematic research review was performed for studies published between 2011 and 2021 in the PubMed, Science Direct, and Google Scholar databases. (3) Results: Initially, the search identified 52 relevant articles. The primary analysis of the titles and abstracts eliminated 22 articles, leaving 30 articles whose full texts were examined. A total of 22 articles met the inclusion criteria. The studies were classified into 3 categories. (4) Conclusions: After evaluating the results of all the studies included in this review, an initial general statement can be made, namely that CO2 lasers are a treatment option worth taking into consideration when approaching oral mucosal lesions. When compared to other types of lasers used in dental practice, the CO2 laser stands out due to its many advantages.

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Garasz, Katarzyna, and Marek Kocik. "Experimental Investigations on Laser Ablation of Aluminum in Sub-Picosecond Regimes." Applied Sciences 10, no. 24 (December 12, 2020): 8883. http://dx.doi.org/10.3390/app10248883.

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Due to high power and ultrashort pulses, femtosecond lasers excel at (but are not limited to) processing materials whose thicknesses are less than 500 microns. Numerous experiments and theoretical analyses testify to the fact that there are solid grounds for the applications of ultrafast laser micromachining. However, with high costs and complexity of these devices, a sub-picosecond laser that might be an alternative when it comes to various micromachining applications, such as patterns and masks in thin metal foils, micro-nozzles, thermo-detectors, MEMS (micro electro-mechanical systems), sensors, etc. Furthermore, the investigation of sub-picosecond laser interactions with matter could provide more knowledge on the ablation mechanisms and experimental verification of existing models for ultrashort pulse regimes. In this article, we present the research on sub-picosecond laser interactions with thin aluminum foil under various laser pulse parameters. Research was conducted with two types of ultrafast lasers: a prototype sub-picosecond Yb:KYW laser (650 fs) and a commercially available femtosecond Ti:S laser (35 fs). The results show how the variables such as pulse width, energy, frequency, wavelength and irradiation time affect the micromachining process.

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Fekrazad, Reza, Mohammad Moharrami, and Nasim Chiniforush. "The Esthetic Crown Lengthening by Er;Cr:YSGG laser: A Case Series." Journal of Lasers in Medical Sciences 9, no. 4 (September 17, 2018): 283–87. http://dx.doi.org/10.15171/jlms.2018.50.

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Introduction: Laser technology as a new modality in dentistry has gained special attention. Among different types of lasers, erbium lasers have gained special attention for management of oral soft and hard tissue simultaneously. This study presents series of cases of crown lengthening (CL) and restorations accomplished by erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG). Case Reports: Seven patients were selected for this study. After complete oral examination and diagnosis, the treatment plan of each patient was designed. All cases needed esthetic CL. In some cases, frenum revision and class V cavity preparation was done by Er;Cr:YSGG laser. All patients treated with Er;Cr:YSGG laser producing a wavelength of 2780 nm (Biolase, Irvine, California, USA); Tip T4, 400 µm Diameter for soft tissue management and Tip G6, 6 mm long, 600 µm diameter for hard tissue management. Results: All patients reflected acceptable results based on clinical evaluation and patients’ declaration of post-surgical status. Conclusion: Using Er;Cr:YSGG laser in class v cavity preparation and flapless CL seemed to be effective and beneficial.

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Brenner, Carsten, Yinghui Hu, Jared Gwaro, Nils Surkamp, Benjamin Döpke, Martin R. Hofmann, Besher Kani, et al. "Near Infrared Diode Laser THz Systems." Advances in Radio Science 16 (September 4, 2018): 167–75. http://dx.doi.org/10.5194/ars-16-167-2018.

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Abstract. The generation and detection of radiation in the THz frequency range can be achieved with many different electronic and photonic concepts. Among the many different photonic THz systems the most versatile are based on diode lasers. In this paper we describe and review the different concepts and optimization ideas for diode laser based THz systems in order to achieve the best performance for different types of THz setups.

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Journal, Baghdad Science. "Theoretical study to find the thermal stress and strain generated in the Wood silica using lasers." Baghdad Science Journal 2, no. 1 (March 6, 2005): 73–80. http://dx.doi.org/10.21123/bsj.2.1.73-80.

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In this research study theory to find the stress and emotion gases in the glass as a result of exposure to pulses of the laser beam has been the study using vehicles three major on-system axes cylindrical (r, 0, z), where I took three models of glass silica glass soda glass fused and shedtwo types of lasers where the study showed that the thermal stresses and emotions ...

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EVANS, M. W. "SPECTRAL SPLITTING DUE TO A CIRCULARLY POLARISED PUMP LASER: LASER ZEEMAN SPECTROSCOPY." Modern Physics Letters B 05, no. 16 (July 10, 1991): 1065–73. http://dx.doi.org/10.1142/s0217984991001301.

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Theoretical prediction is made for various types of molecular Zeeman spectroscopy due to a circularly polarised pump laser, in which optical rectification produces a pattern of spectral splitting mediated by the imaginary antisymmetric part of the frequency-dependent molecular polarisability. The hyperfine part of this splitting, in which the nuclear spin quantum number plays a role, leads to the expectation of laser-induced resonance effects akin to conventional nuclear magnetic resonance (NMR) and electron spin resonance (ESR). Experimental conditions for the observation of "laser Zeeman" spectral effects are defined using double resonance and saturation in mode-locked lasers for ultra high resolution.

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Dompe, Claudia, Lisa Moncrieff, Jacek Matys, Kinga Grzech-Leśniak, Ievgeniia Kocherova, Artur Bryja, Małgorzata Bruska, et al. "Photobiomodulation—Underlying Mechanism and Clinical Applications." Journal of Clinical Medicine 9, no. 6 (June 3, 2020): 1724. http://dx.doi.org/10.3390/jcm9061724.

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The purpose of this study is to explore the possibilities for the application of laser therapy in medicine and dentistry by analyzing lasers’ underlying mechanism of action on different cells, with a special focus on stem cells and mechanisms of repair. The interest in the application of laser therapy in medicine and dentistry has remarkably increased in the last decade. There are different types of lasers available and their usage is well defined by different parameters, such as: wavelength, energy density, power output, and duration of radiation. Laser irradiation can induce a photobiomodulatory (PBM) effect on cells and tissues, contributing to a directed modulation of cell behaviors, enhancing the processes of tissue repair. Photobiomodulation (PBM), also known as low-level laser therapy (LLLT), can induce cell proliferation and enhance stem cell differentiation. Laser therapy is a non-invasive method that contributes to pain relief and reduces inflammation, parallel to the enhanced healing and tissue repair processes. The application of these properties was employed and observed in the treatment of various diseases and conditions, such as diabetes, brain injury, spinal cord damage, dermatological conditions, oral irritation, and in different areas of dentistry.

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Li, Peizhi, Yu Fan, Chonghao Zhang, Zhiyuan Zhu, Wenteng Tian, and Anmin Liu. "Research on Heat Source Model and Weld Profile for Fiber Laser Welding of A304 Stainless Steel Thin Sheet." Advances in Materials Science and Engineering 2018 (2018): 1–12. http://dx.doi.org/10.1155/2018/5895027.

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A heat source model is the key issue for laser welding simulation. The Gaussian heat source model is not suitable to match the actual laser weld profile accurately. Furthermore, fiber lasers are widely recognized to result in good-quality laser beam output, a narrower weld zone, less distortion, and high process efficiency, compared with other types of lasers (such as CO2, Nd : YAG, and diode lasers). At present, there are few heat source models for fiber laser welding. Most of researchers evaluate the weld profile only by the bead width and depth of penetration, which is not suitable for the laser keyhole welding nail-like profile. This paper reports an experimental study and FEA simulation of fiber laser butt welding on 1 mm thick A304 stainless steel. A new heat source model (cylindrical and cylindrical) is established to match the actual weld profile using Marc and Fortran software. Four bead geometry parameters (penetration depth, bead width, waist width, and depth of the waist) are used to compare between the experimental and simulation results. The results show that the heat source model of cylindrical and cylindrical can match the actual shape of the fiber laser welding feasibly. The error range of the penetration depth, bead width, waist width, and depth of the waist between experimental and simulation results is about 4.1 ± 1.6%, 2.9 ± 2.0%, 13.6 ± 7.4/%, and 18.3 ± 8.0%, respectively. In addition, it is found that the depth of penetration is more sensitive to laser power rather than bead width, waist width, and depth of the waist. Welding speed has a similar influence on the depth of penetration, weld width, waist width, and depth of the waist.

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Journal articles on the topic 'Types of lasers'

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