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Nd:YAG laser

April 12, 2024

Nd:YAG (neodymium-doped yttrium aluminum garnet; Nd:Y3Al5O12) is a crystal that is used as a lasing medium for solid-state lasers. The dopant, triply ionized neodymium, Nd(III), typically replaces a small fraction (1%) of the yttrium ions in the host crystal structure of the yttrium aluminum garnet (YAG), since the two ions are of similar size.[1] It is the neodymium ion which provides the lasing activity in the crystal, in the same fashion as red chromium ion in ruby lasers.[1]

Nd:YAG laser with lid open showing frequency-doubled 532 nm green light
Nd:YAG laser rod

Laser operation of Nd:YAG was first demonstrated by J.E. Geusic et al. at Bell Laboratories in 1964.[2]

Technology edit

 
Neodymium ions in various types of ionic crystals, and also in glasses, act as a laser gain medium, typically emitting 1064 nm light from a particular atomic transition in the neodymium ion, after being "pumped" into excitation from an external source

Nd:YAG lasers are optically pumped using a flashtube or laser diodes. These are one of the most common types of laser, and are used for many different applications. Nd:YAG lasers typically emit light with a wavelength of 1064 nm, in the infrared.[3] However, there are also transitions near 946, 1120, 1320, and 1440 nm. Nd:YAG lasers operate in both pulsed and continuous mode. Pulsed Nd:YAG lasers are typically operated in the so-called Q-switching mode: An optical switch is inserted in the laser cavity waiting for a maximum population inversion in the neodymium ions before it opens. Then the light wave can run through the cavity, depopulating the excited laser medium at maximum population inversion. In this Q-switched mode, output powers of 250 megawatts and pulse durations of 10 to 25 nanoseconds have been achieved.[4] The high-intensity pulses may be efficiently frequency doubled to generate laser light at 532 nm, or higher harmonics at 355, 266 and 213 nm.

Nd:YAG absorbs mostly in the bands between 730–760 nm and 790–820 nm.[3] At low current densities krypton flashlamps have higher output in those bands than do the more common xenon lamps, which produce more light at around 900 nm. The former are therefore more efficient for pumping Nd:YAG lasers.[5]

The amount of the neodymium dopant in the material varies according to its use. For continuous wave output, the doping is significantly lower than for pulsed lasers. The lightly doped CW rods can be optically distinguished by being less colored, almost white, while higher-doped rods are pink-purplish.[citation needed]

Other common host materials for neodymium are: YLF (yttrium lithium fluoride, 1047 and 1053 nm), YVO4 (yttrium orthovanadate, 1064 nm), and glass. A particular host material is chosen in order to obtain a desired combination of optical, mechanical, and thermal properties. Nd:YAG lasers and variants are pumped either by flashtubes, continuous gas discharge lamps, or near-infrared laser diodes (DPSS lasers). Prestabilized laser (PSL) types of Nd:YAG lasers have proved to be particularly useful in providing the main beams for gravitational wave interferometers such as LIGO, VIRGO, GEO600 and TAMA.[citation needed]

Applications edit

Medicine edit

 
Slit lamp photograph of posterior capsular opacification visible a few months after implantation of intraocular lens in eye, seen on retroillumination

Nd:YAG lasers are used in ophthalmology to correct posterior capsular opacification,[6] after cataract surgery, for peripheral iridotomy in patients with chronic[7] and acute angle-closure glaucoma,[8] where it has largely superseded surgical iridectomy,[9] for the treatment of vitreous eye floaters,[10] for pan-retinal photocoagulation in the treatment of proliferative diabetic retinopathy,[11] and to damage the retina in ophthalmology animal research.[12]

Nd:YAG lasers emitting light at 1064 nm have been the most widely used laser for laser-induced thermotherapy, in which benign or malignant lesions in various organs are ablated by the beam.

In oncology, Nd:YAG lasers can be used to remove skin cancers.[13] They are also used to reduce benign thyroid nodules,[14] and to destroy primary and secondary malignant liver lesions.[15][16]

To treat benign prostatic hyperplasia (BPH), Nd:YAG lasers can be used for laser prostate surgery—a form of transurethral resection of the prostate.[17][18]

These lasers are also used extensively in the field of cosmetic medicine for laser hair removal and the treatment of minor vascular defects such as spider veins on the face and legs. Nd:YAG lasers are also used to treat venous lake lip lesions.[19] Recently Nd:YAG lasers have been used for treating dissecting cellulitis of the scalp, a rare skin disease.[20]

Using hysteroscopy the Nd:YAG laser has been used for removal of uterine septa within the inside of the uterus.[21]

In podiatry, the Nd:YAG laser is being used to treat onychomycosis, which is fungus infection of the toenail.[22] The merits of laser treatment of these infections are not yet clear, and research is being done to establish effectiveness.[23][24]

Dentistry edit

Nd:YAG dental lasers have been used for the removal of dental caries as an alternative to drill therapy, although evidence supporting its use is of low quality.[25] They have also been used for soft tissue surgeries in the oral cavity, such as gingivectomy,[26][27] periodontal sulcular debridement,[28] LANAP,[29] and pulpotomy.[30] Nd:YAG dental lasers have also been shown to be effective at treating and preventing dental hypersensitivity,[31] as an adjunct for periodontal instrumentation,[32] and for the treatment of recurrent aphthous stomatitis.[33]

Manufacturing edit

Nd:YAG lasers are used in manufacturing for engraving, etching, or marking a variety of metals and plastics, or for metal surface enhancement processes like laser peening.[34] They are extensively used in manufacturing for cutting and welding steel, semiconductors and various alloys. For automotive applications (cutting and welding steel) the power levels are typically 1–5 kW. Super alloy drilling (for gas turbine parts) typically uses pulsed Nd:YAG lasers (millisecond pulses, not Q-switched). Nd:YAG lasers are also employed to make subsurface markings in transparent materials such as glass or acrylic glass and in white and transparent polycarbonate for identity documents. Lasers of up to 2 kW are used for selective laser melting of metals in additive layered manufacturing. In aerospace applications, they can be used to drill cooling holes for enhanced air flow/heat exhaust efficiency.[citation needed]

Nd:YAG lasers are also used in the non-conventional rapid prototyping process laser engineered net shaping (LENS).

Laser peening typically uses a high energy (10 to 40 joule) 10 to 30 nanosecond pulse. The laser beam is focused down to a few millimeters in diameter to deposit gigawatts of power on the surface of a part. Laser peening is unlike other manufacturing processes in that it neither heats or adds material; it is a mechanical process of cold working the metallic component to impart compressive residual stresses. Laser peening is widely used in gas-fired turbine engines in both aerospace and power generation to increase strength and improve resistance to damage and metal fatigue.[35]

Fluid dynamics edit

Nd:YAG lasers can be used for flow visualization techniques in fluid dynamics (for example particle image velocimetry or laser-induced fluorescence).[36]

Biophysics edit

Nd:YAG lasers are frequently used to build optical tweezers for biological applications. This is because Nd:YAG lasers mostly emit at a wavelength of 1064 nm. Biological samples have a low absorption coefficient at this wavelength, as biological samples are usually mostly made up of water. [37] As such, using an Nd:YAG laser minimizes the damage to the biological sample being studied.

Automotive edit

Researchers from Japan's National Institutes of Natural Sciences are developing laser igniters that use YAG chips to ignite fuel in an engine, in place of a spark plug.[38][39] The lasers use several 800 picosecond long pulses to ignite the fuel, producing faster and more uniform ignition. The researchers say that such igniters could yield better performance and fuel economy, with fewer harmful emissions.

Military edit

 
Military surplus Nd:YAG laser rangefinder firing. The laser fires through a collimator, focusing the beam, which blasts a hole through a rubber block, releasing a burst of plasma.

The Nd:YAG laser is the most common laser used in laser designators and laser rangefinders.

During the Iran–Iraq War, Iranian soldiers suffered more than 4000 cases of laser eye injury, caused by a variety of Iraqi sources including tank rangefinders. The 1064 nm wavelength of Nd:YAG is thought to be particularly dangerous, as it is invisible and initial exposure is painless.[40]

The Chinese ZM-87 blinding laser weapon uses a laser of this type, though only 22 have been produced due to their prohibition by the Convention on Certain Conventional Weapons. North Korea is reported to have used one of these weapons against American helicopters in 2003.[41][42]

Cavity ring-down spectroscopy (CRDS) edit

The Nd:YAG may be used in the application of cavity ring-down spectroscopy, which is used to measure the concentration of some light-absorbing substance.[43]

Laser-induced breakdown spectroscopy (LIBS) edit

Main article: Laser-induced breakdown spectroscopy

A range of Nd:YAG lasers are used in analysis of elements in the periodic table. Though the application by itself is fairly new with respect to conventional methods such as XRF or ICP, it has proven to be less time consuming and a cheaper option to test element concentrations. A high-power Nd:YAG laser is focused onto the sample surface to produce plasma. Light from the plasma is captured by spectrometers and the characteristic spectra of each element can be identified, allowing concentrations of elements in the sample to be measured.[citation needed]

Laser pumping edit

Nd:YAG lasers, mainly via their second and third harmonics, are widely used to excite dye lasers either in the liquid[44] or solid state.[45] They are also used as pump sources for vibronically broadened solid-state lasers such as Cr4+:YAG or via the second harmonic for pumping Ti:sapphire lasers.

Additional frequencies edit

For many applications, the infrared light is frequency-doubled or -tripled using nonlinear optical materials such as lithium triborate to obtain visible (532 nm, green) or ultraviolet light.[46] Cesium lithium borate generates the 4th and 5th harmonics of the Nd:YAG 1064 nm fundamental wavelength.[47] A green laser pointer is a frequency doubled Nd:YVO4 diode-pumped solid state laser (DPSS laser).[48] Nd:YAG can be also made to lase at its non-principal wavelength. The line at 946 nm is typically employed in "blue laser pointer" DPSS lasers, where it is doubled to 473 nm.[49][50][51]

Physical and chemical properties of Nd:YAG edit

Properties of YAG crystal edit

  • Formula: Y3Al5O12
  • Molecular weight: 596.7
  • Crystal structure: Cubic
  • Hardness: 8–8.5 (Mohs)[52]
  • Melting point: 1970 °C (3540 °F)
  • Density: 4.55 g/cm3

Refractive index of Nd:YAG edit

Wavelength (μm) Index n (25 °C)
0.8 1.8245
0.9 1.8222
1.0 1.8197
1.2 1.8152
1.4 1.8121
1.5 1.8121

Properties of Nd:YAG @ 25 °C (with 1% Nd doping) edit

  • Formula: Y2.97Nd0.03Al5O12
  • Weight of Nd: 0.725%
  • Atoms of Nd per unit volume: 1.38×1020 /cm3
  • Charge state of Nd: 3+
  • Emission wavelength: 1064 nm
  • Transition: 4F3/2 → 4I11/2
  • Duration of fluorescence: 230 μs[52]
  • Thermal conductivity: 0.14 W·cm−1·K−1
  • Specific heat capacity: 0.59 J·g−1·K−1
  • Thermal expansion: 6.9×10−6 K−1
  • dn/dT: 7.3×10−6 K−1
  • Young's modulus: 3.17×104 K·g/mm−2
  • Poisson's ratio: 0.25
  • Resistance to thermal shock: 790 W·m−1

References and notes edit

  1. ^ a b Koechner §2.3, pp. 48–53.
  2. ^ Geusic, J. E.; Marcos, H. M.; Van Uitert, L. G. (1964). "Laser oscillations in nd-doped yttrium aluminum, yttrium gallium and gadolinium garnets". Applied Physics Letters. 4 (10): 182. Bibcode:1964ApPhL...4..182G. doi:10.1063/1.1753928.
  3. ^ a b Yariv, Amnon (1989). Quantum Electronics (3rd ed.). Wiley. pp. 208–11. ISBN 978-0-471-60997-1.
  4. ^ Walter Koechner (1965) Solid-state laser engineering, Springer-Verlag, p. 507
  5. ^ Koechner §6.1.1, pp. 251–64.
  6. ^ Findl, Oliver; Buehl, Wolf; Bauer, Peter; Sycha, Thomas (2010-02-17). "Interventions for preventing posterior capsule opacification". The Cochrane Database of Systematic Reviews (2): CD003738. doi:10.1002/14651858.CD003738.pub3. ISSN 1469-493X. PMC 10658648. PMID 20166069.
  7. ^ Dias-Santos, Arnaldo; Ferreira, Joana; Abegão Pinto, Luís; Domingues, Isabel; Silva, José Pedro; Cunha, João Paulo; Reina, Maria (April 2015). "Phacoemulsification versus peripheral iridotomy in the management of chronic primary angle closure: long-term follow-up". International Ophthalmology. 35 (2): 173–178. doi:10.1007/s10792-014-9926-8. hdl:10400.17/2093. ISSN 1573-2630. PMID 24728533. S2CID 14929770.
  8. ^ Saunders, D. C. (September 1990). "Acute closed-angle glaucoma and Nd-YAG laser iridotomy". The British Journal of Ophthalmology. 74 (9): 523–525. doi:10.1136/bjo.74.9.523. ISSN 0007-1161. PMC 1042198. PMID 2393642.
  9. ^ Rivera, A. H.; Brown, R. H.; Anderson, D. R. (September 1985). "Laser iridotomy vs surgical iridectomy. Have the indications changed?". Archives of Ophthalmology. 103 (9): 1350–1354. doi:10.1001/archopht.1985.01050090102042. ISSN 0003-9950. PMID 4038128.
  10. ^ Kokavec J, Wu Z, Sherwin JC, Ang AJ, Ang GS (2017). "Nd:YAG laser vitreolysis versus pars plana vitrectomy for vitreous floaters". Cochrane Database Syst Rev. 2017 (6): CD011676. doi:10.1002/14651858.CD011676.pub2. PMC 6481890. PMID 28570745.
  11. ^ Moutray, Tanya; Evans, Jennifer R.; Lois, Noemi; Armstrong, David J.; Peto, Tunde; Azuara-Blanco, Augusto (2018-03-15). "Different lasers and techniques for proliferative diabetic retinopathy". The Cochrane Database of Systematic Reviews. 2018 (3): CD012314. doi:10.1002/14651858.CD012314.pub2. ISSN 1469-493X. PMC 6494342. PMID 29543992.
  12. ^ Kameel Ghaly, Sally; Foad Ghoneim, Dina; Abdelkawi Ahmed, Salwa; Medhat Abdel-Salam, Ahmed (2013). "Histological Evaluation of Retina after Photo Disruption for Vitreous Humor by Q-Switched Neodymium-Doped Yttrium Aluminium Garnet (Nd:YAG) Laser". Journal of Lasers in Medical Sciences. 4 (4): 190–198. ISSN 2008-9783. PMC 4282007. PMID 25606329.
  13. ^ Moskalik, K; A Kozlov; E Demin; E Boiko (2009). "The Efficacy of Facial Skin Cancer Treatment with High-Energy Pulsed Neodymium and Nd:YAG Lasers". Photomedicine Laser Surgery. 27 (2): 345–49. doi:10.1089/pho.2008.2327. PMID 19382838.
  14. ^ Valcavi R, Riganti F, Bertani A, Formisano D, Pacella CM (November 2010). "Percutaneous Laser Ablation of Cold Benign Thyroid Nodules: A 3-Year Follow-Up Study in 122 Patients". Thyroid. 20 (11): 1253–61. doi:10.1089/thy.2010.0189. PMID 20929405.
  15. ^ Pacella CM; Francica G; Di Lascio FM; Arienti V; Antico E; Caspani B; Magnolfi F; Megna AS; Pretolani S; Regine R; Sponza M; Stasi R (June 2009). "Long-term outcome of cirrhotic patients with early hepatocellular carcinoma treated with ultrasound-guided percutaneous laser ablation: a retrospective analysis". Journal of Clinical Oncology. 27 (16): 2615–21. doi:10.1200/JCO.2008.19.0082. PMID 19332729. S2CID 23374952.
  16. ^ Pompili M; Pacella CM; Francica G; Angelico M; Tisone G; Craboledda P; Nicolardi E; Rapaccini GL; Gasbarrini G . (June 2010). "Percutaneous laser ablation of hepatocellular carcinoma in patients with liver cirrhosis awaiting liver transplantation". European Journal of Radiology. 74 (3): e6–e11. doi:10.1016/j.ejrad.2009.03.012. PMID 19345541.
  17. ^ Sun, Feng; Sun, Xincheng; Shi, Qinglu; Zhai, Yuzhang (December 2018). "Transurethral procedures in the treatment of benign prostatic hyperplasia: A systematic review and meta-analysis of effectiveness and complications". Medicine. 97 (51): e13360. doi:10.1097/MD.0000000000013360. ISSN 1536-5964. PMC 6320039. PMID 30572440.
  18. ^ Costello, A. J.; Johnson, D. E.; Bolton, D. M. (1992). "Nd:YAG laser ablation of the prostate as a treatment for benign prostatic hypertrophy". Lasers in Surgery and Medicine. 12 (2): 121–124. doi:10.1002/lsm.1900120202. ISSN 0196-8092. PMID 1374142. S2CID 39538383.
  19. ^ Azevedo, L. H; Galletta, V. C; De Paula Eduardo, C; Migliari, D. A (2010). "Venous Lake of the Lips Treated Using Photocoagulation with High-Intensity Diode Laser". Photomedicine and Laser Surgery. 28 (2): 263–265. doi:10.1089/pho.2009.2564. PMC 2957073. PMID 19811083.
  20. ^ Krasner BD; Hamzavi FH; Murakawa GJ; Hamzavi IH (August 2006). "Dissecting cellulitis treated with the long-pulsed Nd:YAG laser". Dermatologic Surgery. 32 (8): 1039–44. doi:10.1111/j.1524-4725.2006.32227.x. PMID 16918566. S2CID 31317584.
  21. ^ Yang J, Yin TL, Xu WM, Xia LB, Li AB, Hu J (2006). "Reproductive outcome of septate uterus after hysteroscopic treatment with neodymium:YAG laser". Photomedicine Laser Surgery. 24 (5): 625. doi:10.1089/pho.2006.24.625. PMID 17069494.
  22. ^ Ledon, Jennifer A.; Savas, Jessica; Franca, Katlein; Chacon, Anna; Nouri, Keyvan (2012). "Laser and light therapy for onychomycosis: a systematic review". Lasers in Medical Science. 29 (2): 823–29. doi:10.1007/s10103-012-1232-y. ISSN 0268-8921. PMID 23179307. S2CID 7950300.
  23. ^ Mozena, John; Haverstock, Brent (May 2010). "Laser care for onychomycosis: can it be effective?". Podiatry Today. 23 (5): 54–59.
  24. ^ Mozena, John D.; Mitnick, Joshua P. (October 2009). "Emerging concepts in treating onychomycosis". Podiatry Today. 22 (10): 46–51.
  25. ^ Montedori, Alessandro; Abraha, Iosief; Orso, Massimiliano; D'Errico, Potito Giuseppe; Pagano, Stefano; Lombardo, Guido (2016-09-26). "Lasers for caries removal in deciduous and permanent teeth". The Cochrane Database of Systematic Reviews. 2016 (9): CD010229. doi:10.1002/14651858.CD010229.pub2. ISSN 1469-493X. PMC 6457657. PMID 27666123.
  26. ^ Cortes, M. (April 1999). "Nd:YAG laser-assisted gingivectomy, bleaching, and porcelain laminates, Part 2". Dentistry Today. 18 (4): 52–55. ISSN 8750-2186. PMID 10765801.
  27. ^ De Benedittis, Michele; Petruzzi, Massimo; Pastore, Luca; Inchingolo, Francesco; Serpico, Rosario (February 2007). "Nd:YAG laser for gingivectomy in Sturge-Weber syndrome". Journal of Oral and Maxillofacial Surgery. 65 (2): 314–316. doi:10.1016/j.joms.2006.05.011. ISSN 0278-2391. PMID 17236940.
  28. ^ David M. Harris, Robert H. Gregg, Delwin K. McCarthy, Leigh E. Colby, Lloyd V. Tilt, "Sulcular debridement with pulsed Nd:YAG," Proc. SPIE 4610, Lasers in Dentistry VIII, (3 June 2002); doi: 10.1117/12.469328
  29. ^ Yukna, Raymond A.; Carr, Ronald L.; Evans, Gerald H. (December 2007). "Histologic evaluation of an Nd:YAG laser-assisted new attachment procedure in humans". The International Journal of Periodontics & Restorative Dentistry. 27 (6): 577–587. ISSN 0198-7569. PMID 18092452.
  30. ^ De Coster, Peter; Rajasekharan, Sivaprakash; Martens, Luc (November 2013). "Laser-assisted pulpotomy in primary teeth: a systematic review". International Journal of Paediatric Dentistry. 23 (6): 389–399. doi:10.1111/ipd.12014. ISSN 1365-263X. PMID 23171469.
  31. ^ Rezazadeh, Fahimeh; Dehghanian, Paria; Jafarpour, Dana (2019). "Laser Effects on the Prevention and Treatment of Dentinal Hypersensitivity: A Systematic Review". Journal of Lasers in Medical Sciences. 10 (1): 1–11. doi:10.15171/jlms.2019.01. ISSN 2008-9783. PMC 6499583. PMID 31360362.
  32. ^ Roncati, Marisa; Gariffo, Annalisa (April 2014). "Systematic review of the adjunctive use of diode and Nd:YAG lasers for nonsurgical periodontal instrumentation". Photomedicine and Laser Surgery. 32 (4): 186–197. doi:10.1089/pho.2013.3695. ISSN 1557-8550. PMID 24697584.
  33. ^ Suter, Valerie G. A.; Sjölund, Sophia; Bornstein, Michael M. (May 2017). "Effect of laser on pain relief and wound healing of recurrent aphthous stomatitis: a systematic review". Lasers in Medical Science. 32 (4): 953–963. doi:10.1007/s10103-017-2184-z. ISSN 1435-604X. PMID 28345122. S2CID 3853214.
  34. ^ Studies on laser peening of spring steel for automotive applications | Ranganathan Kandasamy - Academia.edu
  35. ^ "How laser peening works". LSP Technologies. Retrieved 2022-12-24.
  36. ^ Palafox, Gilbert N.; Wicker, Ryan B.; Elkins, Christopher J. (2003). "Rapid in-vitro physiologic flow experimentation using rapid prototyping and particle image velocimetry" (PDF). 2003 Summer Bioengineering Conference: 419. Retrieved 2007-10-10.
  37. ^ D. J. Stevenson; T. K. Lake; B. Agate; V. Gárcés-Chávez; K. Dholakia; F. Gunn-Moore (2006-10-16). "Optically guided neuronal growth at near infrared wavelengths". Optics Express. 14 (21): 9786–93. Bibcode:2006OExpr..14.9786S. doi:10.1364/OE.14.009786. PMC 2869025. PMID 19529370.
  38. ^ Coxworth, Ben (April 21, 2011). "Laser igniters could spell the end for the humble spark plug". Gizmag. Retrieved March 30, 2012.
  39. ^ Pavel, Nicolaie; et al. (2011). "Composite, all-ceramics, high-peak power Nd:YAG/Cr4+:YAG monolithic micro-laser with multiple-beam output for engine ignition". Optics Express. 19 (10): 9378–84. Bibcode:2011OExpr..19.9378P. doi:10.1364/OE.19.009378. PMID 21643194.
  40. ^ "Anti-Personnel Lasers - Iraq Special Weapons".
  41. ^ Fisher, Franklin (2003-05-14). "U.S. says Apache copters were targeted by laser weapons near Korean DMZ". Stars and Stripes. Retrieved 2016-12-20.
  42. ^ Lister, Tim. . CNN. Archived from the original on 2010-11-26. Retrieved 24 December 2010.
  43. ^ "Cavity Ring Down Spectroscopy (CRDS) : Atmospheric Chemistry: HIRAC Group". hirac.leeds.ac.uk. Retrieved 2023-01-04.
  44. ^ F. P. Schäfer (Ed.), Dye Lasers (Springer-Verlag, Berlin, 1990).
  45. ^ F. J. Duarte, Tunable Laser Optics (Elsevier-Academic, New York, 2003).
  46. ^ Paschotta, Rüdiger (2008-01-15). "Frequency Doubling". Field Guide to Lasers. Vol. FG12. doi:10.1117/3.767474.p110. ISBN 9780819478269.
  47. ^ Komatsu, R.; Sugawara, T.; Sassa, K.; Sarukura, N.; Liu, Z.; Izumida, S.; Segawa, Y.; Uda, S.; Fukuda, T.; Yamanouchi, K. (1997-06-30). "Growth and ultraviolet application of Li2B4O7 crystals: Generation of the fourth and fifth harmonics of Nd:Y3Al5O12 lasers". Applied Physics Letters. 70 (26): 3492–3494. Bibcode:1997ApPhL..70.3492K. doi:10.1063/1.119210. ISSN 0003-6951.
  48. ^ "Green Lasers". www.optotronics.com. Retrieved 2021-05-05.
  49. ^ "Nd:YAG laser". www.scientificlib.com. Retrieved 2021-05-05.
  50. ^ Fan, T. Y.; Byer, R. L. (1987-10-01). "Continuous-wave operation of a room-temperature, diode-laser-pumped, 946-nm Nd:YAG laser". Optics Letters. 12 (10): 809–811. Bibcode:1987OptL...12..809F. doi:10.1364/ol.12.000809. ISSN 0146-9592. PMID 19741880.
  51. ^ Keiderling, Tim (2013). "Chem 542 Techniques of Optical Spectroscopy in Analytical Chemistry". www2.chem.uic.edu. http://www2.chem.uic.edu/tak/chem52413/notes3/notes3b-13sol.pdf. Retrieved 2021-05-05.
  52. ^ a b Paschotta, Rüdiger. "YAG Lasers". Encyclopedia of Laser Physics and Technology. RP Photonics. Retrieved 2018-01-16.

April 12, 2024
laser, neodymium, doped, yttrium, aluminum, garnet, y3al5o12, crystal, that, used, lasing, medium, solid, state, lasers, dopant, triply, ionized, neodymium, typically, replaces, small, fraction, yttrium, ions, host, crystal, structure, yttrium, aluminum, garne. Nd YAG neodymium doped yttrium aluminum garnet Nd Y3Al5O12 is a crystal that is used as a lasing medium for solid state lasers The dopant triply ionized neodymium Nd III typically replaces a small fraction 1 of the yttrium ions in the host crystal structure of the yttrium aluminum garnet YAG since the two ions are of similar size 1 It is the neodymium ion which provides the lasing activity in the crystal in the same fashion as red chromium ion in ruby lasers 1 Nd YAG laser with lid open showing frequency doubled 532 nm green lightNd YAG laser rodLaser operation of Nd YAG was first demonstrated by J E Geusic et al at Bell Laboratories in 1964 2 Contents 1 Technology 2 Applications 2 1 Medicine 2 2 Dentistry 2 3 Manufacturing 2 4 Fluid dynamics 2 5 Biophysics 2 6 Automotive 2 7 Military 2 8 Cavity ring down spectroscopy CRDS 2 9 Laser induced breakdown spectroscopy LIBS 2 10 Laser pumping 3 Additional frequencies 4 Physical and chemical properties of Nd YAG 4 1 Properties of YAG crystal 4 2 Refractive index of Nd YAG 4 3 Properties of Nd YAG 25 C with 1 Nd doping 5 References and notesTechnology edit nbsp Neodymium ions in various types of ionic crystals and also in glasses act as a laser gain medium typically emitting 1064 nm light from a particular atomic transition in the neodymium ion after being pumped into excitation from an external sourceNd YAG lasers are optically pumped using a flashtube or laser diodes These are one of the most common types of laser and are used for many different applications Nd YAG lasers typically emit light with a wavelength of 1064 nm in the infrared 3 However there are also transitions near 946 1120 1320 and 1440 nm Nd YAG lasers operate in both pulsed and continuous mode Pulsed Nd YAG lasers are typically operated in the so called Q switching mode An optical switch is inserted in the laser cavity waiting for a maximum population inversion in the neodymium ions before it opens Then the light wave can run through the cavity depopulating the excited laser medium at maximum population inversion In this Q switched mode output powers of 250 megawatts and pulse durations of 10 to 25 nanoseconds have been achieved 4 The high intensity pulses may be efficiently frequency doubled to generate laser light at 532 nm or higher harmonics at 355 266 and 213 nm Nd YAG absorbs mostly in the bands between 730 760 nm and 790 820 nm 3 At low current densities krypton flashlamps have higher output in those bands than do the more common xenon lamps which produce more light at around 900 nm The former are therefore more efficient for pumping Nd YAG lasers 5 The amount of the neodymium dopant in the material varies according to its use For continuous wave output the doping is significantly lower than for pulsed lasers The lightly doped CW rods can be optically distinguished by being less colored almost white while higher doped rods are pink purplish citation needed Other common host materials for neodymium are YLF yttrium lithium fluoride 1047 and 1053 nm YVO4 yttrium orthovanadate 1064 nm and glass A particular host material is chosen in order to obtain a desired combination of optical mechanical and thermal properties Nd YAG lasers and variants are pumped either by flashtubes continuous gas discharge lamps or near infrared laser diodes DPSS lasers Prestabilized laser PSL types of Nd YAG lasers have proved to be particularly useful in providing the main beams for gravitational wave interferometers such as LIGO VIRGO GEO600 and TAMA citation needed Applications editMedicine edit nbsp Slit lamp photograph of posterior capsular opacification visible a few months after implantation of intraocular lens in eye seen on retroilluminationNd YAG lasers are used in ophthalmology to correct posterior capsular opacification 6 after cataract surgery for peripheral iridotomy in patients with chronic 7 and acute angle closure glaucoma 8 where it has largely superseded surgical iridectomy 9 for the treatment of vitreous eye floaters 10 for pan retinal photocoagulation in the treatment of proliferative diabetic retinopathy 11 and to damage the retina in ophthalmology animal research 12 Nd YAG lasers emitting light at 1064 nm have been the most widely used laser for laser induced thermotherapy in which benign or malignant lesions in various organs are ablated by the beam In oncology Nd YAG lasers can be used to remove skin cancers 13 They are also used to reduce benign thyroid nodules 14 and to destroy primary and secondary malignant liver lesions 15 16 To treat benign prostatic hyperplasia BPH Nd YAG lasers can be used for laser prostate surgery a form of transurethral resection of the prostate 17 18 These lasers are also used extensively in the field of cosmetic medicine for laser hair removal and the treatment of minor vascular defects such as spider veins on the face and legs Nd YAG lasers are also used to treat venous lake lip lesions 19 Recently Nd YAG lasers have been used for treating dissecting cellulitis of the scalp a rare skin disease 20 Using hysteroscopy the Nd YAG laser has been used for removal of uterine septa within the inside of the uterus 21 In podiatry the Nd YAG laser is being used to treat onychomycosis which is fungus infection of the toenail 22 The merits of laser treatment of these infections are not yet clear and research is being done to establish effectiveness 23 24 Dentistry edit Nd YAG dental lasers have been used for the removal of dental caries as an alternative to drill therapy although evidence supporting its use is of low quality 25 They have also been used for soft tissue surgeries in the oral cavity such as gingivectomy 26 27 periodontal sulcular debridement 28 LANAP 29 and pulpotomy 30 Nd YAG dental lasers have also been shown to be effective at treating and preventing dental hypersensitivity 31 as an adjunct for periodontal instrumentation 32 and for the treatment of recurrent aphthous stomatitis 33 Manufacturing edit Nd YAG lasers are used in manufacturing for engraving etching or marking a variety of metals and plastics or for metal surface enhancement processes like laser peening 34 They are extensively used in manufacturing for cutting and welding steel semiconductors and various alloys For automotive applications cutting and welding steel the power levels are typically 1 5 kW Super alloy drilling for gas turbine parts typically uses pulsed Nd YAG lasers millisecond pulses not Q switched Nd YAG lasers are also employed to make subsurface markings in transparent materials such as glass or acrylic glass and in white and transparent polycarbonate for identity documents Lasers of up to 2 kW are used for selective laser melting of metals in additive layered manufacturing In aerospace applications they can be used to drill cooling holes for enhanced air flow heat exhaust efficiency citation needed Nd YAG lasers are also used in the non conventional rapid prototyping process laser engineered net shaping LENS Laser peening typically uses a high energy 10 to 40 joule 10 to 30 nanosecond pulse The laser beam is focused down to a few millimeters in diameter to deposit gigawatts of power on the surface of a part Laser peening is unlike other manufacturing processes in that it neither heats or adds material it is a mechanical process of cold working the metallic component to impart compressive residual stresses Laser peening is widely used in gas fired turbine engines in both aerospace and power generation to increase strength and improve resistance to damage and metal fatigue 35 Fluid dynamics edit Nd YAG lasers can be used for flow visualization techniques in fluid dynamics for example particle image velocimetry or laser induced fluorescence 36 Biophysics edit Nd YAG lasers are frequently used to build optical tweezers for biological applications This is because Nd YAG lasers mostly emit at a wavelength of 1064 nm Biological samples have a low absorption coefficient at this wavelength as biological samples are usually mostly made up of water 37 As such using an Nd YAG laser minimizes the damage to the biological sample being studied Automotive edit Researchers from Japan s National Institutes of Natural Sciences are developing laser igniters that use YAG chips to ignite fuel in an engine in place of a spark plug 38 39 The lasers use several 800 picosecond long pulses to ignite the fuel producing faster and more uniform ignition The researchers say that such igniters could yield better performance and fuel economy with fewer harmful emissions Military edit nbsp Military surplus Nd YAG laser rangefinder firing The laser fires through a collimator focusing the beam which blasts a hole through a rubber block releasing a burst of plasma The Nd YAG laser is the most common laser used in laser designators and laser rangefinders During the Iran Iraq War Iranian soldiers suffered more than 4000 cases of laser eye injury caused by a variety of Iraqi sources including tank rangefinders The 1064 nm wavelength of Nd YAG is thought to be particularly dangerous as it is invisible and initial exposure is painless 40 The Chinese ZM 87 blinding laser weapon uses a laser of this type though only 22 have been produced due to their prohibition by the Convention on Certain Conventional Weapons North Korea is reported to have used one of these weapons against American helicopters in 2003 41 42 Cavity ring down spectroscopy CRDS edit The Nd YAG may be used in the application of cavity ring down spectroscopy which is used to measure the concentration of some light absorbing substance 43 Laser induced breakdown spectroscopy LIBS edit Main article Laser induced breakdown spectroscopy A range of Nd YAG lasers are used in analysis of elements in the periodic table Though the application by itself is fairly new with respect to conventional methods such as XRF or ICP it has proven to be less time consuming and a cheaper option to test element concentrations A high power Nd YAG laser is focused onto the sample surface to produce plasma Light from the plasma is captured by spectrometers and the characteristic spectra of each element can be identified allowing concentrations of elements in the sample to be measured citation needed Laser pumping edit Nd YAG lasers mainly via their second and third harmonics are widely used to excite dye lasers either in the liquid 44 or solid state 45 They are also used as pump sources for vibronically broadened solid state lasers such as Cr4 YAG or via the second harmonic for pumping Ti sapphire lasers Additional frequencies editFor many applications the infrared light is frequency doubled or tripled using nonlinear optical materials such as lithium triborate to obtain visible 532 nm green or ultraviolet light 46 Cesium lithium borate generates the 4th and 5th harmonics of the Nd YAG 1064 nm fundamental wavelength 47 A green laser pointer is a frequency doubled Nd YVO4 diode pumped solid state laser DPSS laser 48 Nd YAG can be also made to lase at its non principal wavelength The line at 946 nm is typically employed in blue laser pointer DPSS lasers where it is doubled to 473 nm 49 50 51 Physical and chemical properties of Nd YAG editProperties of YAG crystal edit Formula Y3Al5O12 Molecular weight 596 7 Crystal structure Cubic Hardness 8 8 5 Mohs 52 Melting point 1970 C 3540 F Density 4 55 g cm3Refractive index of Nd YAG edit Wavelength mm Index n 25 C 0 8 1 82450 9 1 82221 0 1 81971 2 1 81521 4 1 81211 5 1 8121Properties of Nd YAG 25 C with 1 Nd doping edit Formula Y2 97Nd0 03Al5O12 Weight of Nd 0 725 Atoms of Nd per unit volume 1 38 1020 cm3 Charge state of Nd 3 Emission wavelength 1064 nm Transition 4F3 2 4I11 2 Duration of fluorescence 230 ms 52 Thermal conductivity 0 14 W cm 1 K 1 Specific heat capacity 0 59 J g 1 K 1 Thermal expansion 6 9 10 6 K 1 dn dT 7 3 10 6 K 1 Young s modulus 3 17 104 K g mm 2 Poisson s ratio 0 25 Resistance to thermal shock 790 W m 1References and notes edit a b Koechner 2 3 pp 48 53 Geusic J E Marcos H M Van Uitert L G 1964 Laser oscillations in nd doped yttrium aluminum yttrium gallium and gadolinium garnets Applied Physics Letters 4 10 182 Bibcode 1964ApPhL 4 182G doi 10 1063 1 1753928 a b Yariv Amnon 1989 Quantum Electronics 3rd ed Wiley pp 208 11 ISBN 978 0 471 60997 1 Walter Koechner 1965 Solid state laser engineering Springer Verlag p 507 Koechner 6 1 1 pp 251 64 Findl Oliver Buehl Wolf Bauer Peter Sycha Thomas 2010 02 17 Interventions for preventing posterior capsule opacification The Cochrane Database of Systematic Reviews 2 CD003738 doi 10 1002 14651858 CD003738 pub3 ISSN 1469 493X PMC 10658648 PMID 20166069 Dias Santos Arnaldo Ferreira Joana Abegao Pinto Luis Domingues Isabel Silva Jose Pedro Cunha Joao Paulo Reina Maria April 2015 Phacoemulsification versus peripheral iridotomy in the management of chronic primary angle closure long term follow up International Ophthalmology 35 2 173 178 doi 10 1007 s10792 014 9926 8 hdl 10400 17 2093 ISSN 1573 2630 PMID 24728533 S2CID 14929770 Saunders D C September 1990 Acute closed angle glaucoma and Nd YAG laser iridotomy The British Journal of Ophthalmology 74 9 523 525 doi 10 1136 bjo 74 9 523 ISSN 0007 1161 PMC 1042198 PMID 2393642 Rivera A H Brown R H Anderson D R September 1985 Laser iridotomy vs surgical iridectomy Have the indications changed Archives of Ophthalmology 103 9 1350 1354 doi 10 1001 archopht 1985 01050090102042 ISSN 0003 9950 PMID 4038128 Kokavec J Wu Z Sherwin JC Ang AJ Ang GS 2017 Nd YAG laser vitreolysis versus pars plana vitrectomy for vitreous floaters Cochrane Database Syst Rev 2017 6 CD011676 doi 10 1002 14651858 CD011676 pub2 PMC 6481890 PMID 28570745 Moutray Tanya Evans Jennifer R Lois Noemi Armstrong David J Peto Tunde Azuara Blanco Augusto 2018 03 15 Different lasers and techniques for proliferative diabetic retinopathy The Cochrane Database of Systematic Reviews 2018 3 CD012314 doi 10 1002 14651858 CD012314 pub2 ISSN 1469 493X PMC 6494342 PMID 29543992 Kameel Ghaly Sally Foad Ghoneim Dina Abdelkawi Ahmed Salwa Medhat Abdel Salam Ahmed 2013 Histological Evaluation of Retina after Photo Disruption for Vitreous Humor by Q Switched Neodymium Doped Yttrium Aluminium Garnet Nd YAG Laser Journal of Lasers in Medical Sciences 4 4 190 198 ISSN 2008 9783 PMC 4282007 PMID 25606329 Moskalik K A Kozlov E Demin E Boiko 2009 The Efficacy of Facial Skin Cancer Treatment with High Energy Pulsed Neodymium and Nd YAG Lasers Photomedicine Laser Surgery 27 2 345 49 doi 10 1089 pho 2008 2327 PMID 19382838 Valcavi R Riganti F Bertani A Formisano D Pacella CM November 2010 Percutaneous Laser Ablation of Cold Benign Thyroid Nodules A 3 Year Follow Up Study in 122 Patients Thyroid 20 11 1253 61 doi 10 1089 thy 2010 0189 PMID 20929405 Pacella CM Francica G Di Lascio FM Arienti V Antico E Caspani B Magnolfi F Megna AS Pretolani S Regine R Sponza M Stasi R June 2009 Long term outcome of cirrhotic patients with early hepatocellular carcinoma treated with ultrasound guided percutaneous laser ablation a retrospective analysis Journal of Clinical Oncology 27 16 2615 21 doi 10 1200 JCO 2008 19 0082 PMID 19332729 S2CID 23374952 Pompili M Pacella CM Francica G Angelico M Tisone G Craboledda P Nicolardi E Rapaccini GL Gasbarrini G June 2010 Percutaneous laser ablation of hepatocellular carcinoma in patients with liver cirrhosis awaiting liver transplantation European Journal of Radiology 74 3 e6 e11 doi 10 1016 j ejrad 2009 03 012 PMID 19345541 Sun Feng Sun Xincheng Shi Qinglu Zhai Yuzhang December 2018 Transurethral procedures in the treatment of benign prostatic hyperplasia A systematic review and meta analysis of effectiveness and complications Medicine 97 51 e13360 doi 10 1097 MD 0000000000013360 ISSN 1536 5964 PMC 6320039 PMID 30572440 Costello A J Johnson D E Bolton D M 1992 Nd YAG laser ablation of the prostate as a treatment for benign prostatic hypertrophy Lasers in Surgery and Medicine 12 2 121 124 doi 10 1002 lsm 1900120202 ISSN 0196 8092 PMID 1374142 S2CID 39538383 Azevedo L H Galletta V C De Paula Eduardo C Migliari D A 2010 Venous Lake of the Lips Treated Using Photocoagulation with High Intensity Diode Laser Photomedicine and Laser Surgery 28 2 263 265 doi 10 1089 pho 2009 2564 PMC 2957073 PMID 19811083 Krasner BD Hamzavi FH Murakawa GJ Hamzavi IH August 2006 Dissecting cellulitis treated with the long pulsed Nd YAG laser Dermatologic Surgery 32 8 1039 44 doi 10 1111 j 1524 4725 2006 32227 x PMID 16918566 S2CID 31317584 Yang J Yin TL Xu WM Xia LB Li AB Hu J 2006 Reproductive outcome of septate uterus after hysteroscopic treatment with neodymium YAG laser Photomedicine Laser Surgery 24 5 625 doi 10 1089 pho 2006 24 625 PMID 17069494 Ledon Jennifer A Savas Jessica Franca Katlein Chacon Anna Nouri Keyvan 2012 Laser and light therapy for onychomycosis a systematic review Lasers in Medical Science 29 2 823 29 doi 10 1007 s10103 012 1232 y ISSN 0268 8921 PMID 23179307 S2CID 7950300 Mozena John Haverstock Brent May 2010 Laser care for onychomycosis can it be effective Podiatry Today 23 5 54 59 Mozena John D Mitnick Joshua P October 2009 Emerging concepts in treating onychomycosis Podiatry Today 22 10 46 51 Montedori Alessandro Abraha Iosief Orso Massimiliano D Errico Potito Giuseppe Pagano Stefano Lombardo Guido 2016 09 26 Lasers for caries removal in deciduous and permanent teeth The Cochrane Database of Systematic Reviews 2016 9 CD010229 doi 10 1002 14651858 CD010229 pub2 ISSN 1469 493X PMC 6457657 PMID 27666123 Cortes M April 1999 Nd YAG laser assisted gingivectomy bleaching and porcelain laminates Part 2 Dentistry Today 18 4 52 55 ISSN 8750 2186 PMID 10765801 De Benedittis Michele Petruzzi Massimo Pastore Luca Inchingolo Francesco Serpico Rosario February 2007 Nd YAG laser for gingivectomy in Sturge Weber syndrome Journal of Oral and Maxillofacial Surgery 65 2 314 316 doi 10 1016 j joms 2006 05 011 ISSN 0278 2391 PMID 17236940 David M Harris Robert H Gregg Delwin K McCarthy Leigh E Colby Lloyd V Tilt Sulcular debridement with pulsed Nd YAG Proc SPIE 4610 Lasers in Dentistry VIII 3 June 2002 doi 10 1117 12 469328 Yukna Raymond A Carr Ronald L Evans Gerald H December 2007 Histologic evaluation of an Nd YAG laser assisted new attachment procedure in humans The International Journal of Periodontics amp Restorative Dentistry 27 6 577 587 ISSN 0198 7569 PMID 18092452 De Coster Peter Rajasekharan Sivaprakash Martens Luc November 2013 Laser assisted pulpotomy in primary teeth a systematic review International Journal of Paediatric Dentistry 23 6 389 399 doi 10 1111 ipd 12014 ISSN 1365 263X PMID 23171469 Rezazadeh Fahimeh Dehghanian Paria Jafarpour Dana 2019 Laser Effects on the Prevention and Treatment of Dentinal Hypersensitivity A Systematic Review Journal of Lasers in Medical Sciences 10 1 1 11 doi 10 15171 jlms 2019 01 ISSN 2008 9783 PMC 6499583 PMID 31360362 Roncati Marisa Gariffo Annalisa April 2014 Systematic review of the adjunctive use of diode and Nd YAG lasers for nonsurgical periodontal instrumentation Photomedicine and Laser Surgery 32 4 186 197 doi 10 1089 pho 2013 3695 ISSN 1557 8550 PMID 24697584 Suter Valerie G A Sjolund Sophia Bornstein Michael M May 2017 Effect of laser on pain relief and wound healing of recurrent aphthous stomatitis a systematic review Lasers in Medical Science 32 4 953 963 doi 10 1007 s10103 017 2184 z ISSN 1435 604X PMID 28345122 S2CID 3853214 Studies on laser peening of spring steel for automotive applications Ranganathan Kandasamy Academia edu How laser peening works LSP Technologies Retrieved 2022 12 24 Palafox Gilbert N Wicker Ryan B Elkins Christopher J 2003 Rapid in vitro physiologic flow experimentation using rapid prototyping and particle image velocimetry PDF 2003 Summer Bioengineering Conference 419 Retrieved 2007 10 10 D J Stevenson T K Lake B Agate V Garces Chavez K Dholakia F Gunn Moore 2006 10 16 Optically guided neuronal growth at near infrared wavelengths Optics Express 14 21 9786 93 Bibcode 2006OExpr 14 9786S doi 10 1364 OE 14 009786 PMC 2869025 PMID 19529370 Coxworth Ben April 21 2011 Laser igniters could spell the end for the humble spark plug Gizmag Retrieved March 30 2012 Pavel Nicolaie et al 2011 Composite all ceramics high peak power Nd YAG Cr4 YAG monolithic micro laser with multiple beam output for engine ignition Optics Express 19 10 9378 84 Bibcode 2011OExpr 19 9378P doi 10 1364 OE 19 009378 PMID 21643194 Anti Personnel Lasers Iraq Special Weapons Fisher Franklin 2003 05 14 U S says Apache copters were targeted by laser weapons near Korean DMZ Stars and Stripes Retrieved 2016 12 20 Lister Tim North Korea s military aging but sizeable CNN Archived from the original on 2010 11 26 Retrieved 24 December 2010 Cavity Ring Down Spectroscopy CRDS Atmospheric Chemistry HIRAC Group hirac leeds ac uk Retrieved 2023 01 04 F P Schafer Ed Dye Lasers Springer Verlag Berlin 1990 F J Duarte Tunable Laser Optics Elsevier Academic New York 2003 Paschotta Rudiger 2008 01 15 Frequency Doubling Field Guide to Lasers Vol FG12 doi 10 1117 3 767474 p110 ISBN 9780819478269 Komatsu R Sugawara T Sassa K Sarukura N Liu Z Izumida S Segawa Y Uda S Fukuda T Yamanouchi K 1997 06 30 Growth and ultraviolet application of Li2B4O7 crystals Generation of the fourth and fifth harmonics of Nd Y3Al5O12 lasers Applied Physics Letters 70 26 3492 3494 Bibcode 1997ApPhL 70 3492K doi 10 1063 1 119210 ISSN 0003 6951 Green Lasers www optotronics com Retrieved 2021 05 05 Nd YAG laser www scientificlib com Retrieved 2021 05 05 Fan T Y Byer R L 1987 10 01 Continuous wave operation of a room temperature diode laser pumped 946 nm Nd YAG laser Optics Letters 12 10 809 811 Bibcode 1987OptL 12 809F doi 10 1364 ol 12 000809 ISSN 0146 9592 PMID 19741880 Keiderling Tim 2013 Chem 542 Techniques of Optical Spectroscopy in Analytical Chemistry www2 chem uic edu http www2 chem uic edu tak chem52413 notes3 notes3b 13sol pdf Retrieved 2021 05 05 a b Paschotta Rudiger YAG Lasers Encyclopedia of Laser Physics and Technology RP Photonics Retrieved 2018 01 16 Siegman Anthony E 1986 Lasers University Science Books ISBN 978 0 935702 11 8 Koechner Walter 1988 Solid State Laser Engineering 2nd ed Springer Verlag ISBN 978 3 540 18747 9 Retrieved from https en wikipedia org w index php title Nd YAG laser amp oldid 1199725180, wikipedia, wiki, book, books, library,

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