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. It is the neodymium ion which provides the lasing activity in the crystal, in the same fashion as red chromium ion in ruby lasers.
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. 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. 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. 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. 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.
Slit lamp photo 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, a condition that may occur after cataract surgery, and for peripheral iridotomy in patients with acute angle-closure glaucoma, where it has superseded surgical iridectomy. Frequency-doubled Nd:YAG lasers (wavelength 532 nm) are used for pan-retinal photocoagulation in patients with diabetic retinopathy. In certain cases these lasers are also used to treat eye floaters. 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. They are also used to reduce benign thyroid nodules, and to destroy primary and secondary malignant liver lesions. To treat benign prostatic hyperplasia (BPH), Nd:YAG lasers can be used for laser prostate surgery—a form of transurethral resection of the prostate. 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. Recently Nd:YAG lasers have been used for treating dissecting cellulitis of the scalp, a rare skin disease. Using hysteroscopy the Nd:YAG laser has been used for removal of uterine septa within the inside of the uterus. In podiatry, the Nd:YAG laser is being used to treat onychomycosis, which is fungus infection of the toenail. The merits of laser treatment of these infections are not yet clear, and research is being done to establish effectiveness.
Nd:YAG dental lasers are used for soft tissue surgeries in the oral cavity, such as gingivectomy, periodontal sulcular debridement, LANAP, pulpotomy, frenectomy, biopsy, and coagulation of graft donor sites.
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. 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. 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. Nd:YAG lasers are also used in the non-conventional rapid prototyping process laser engineered net shaping (LENS). Laser peening typically uses high energy (10 to 40 Joule), 10 to 30 nanosecond pulse, flashed laser systems to generate gigawatts of power on the surface of a part by focusing the laser beam down to a few millimeters in diameter. Laser peening is unlike the 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 for component damage tolerance improvement and fatigue life and strength increase.
Fluid dynamics Nd:YAG lasers can be used for flow visualization techniques in fluid dynamics (for example particle image velocimetry or laser-induced fluorescence).
Biophysics 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. As such, using an Nd:YAG laser minimizes the damage to the biological sample being studied.
Automotive 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. 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 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.
Cavity ring-down spectroscopy (CRDS) 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.
Laser-induced breakdown spectroscopy (LIBS) 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.
Laser pumping Nd:YAG lasers, mainly via their second and third harmonics, are widely used to excite dye lasers either in the liquid or solid state. 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.
VY Optoelectronics Co.,Ltd. has the major large-size YAG single crystal products, like Nd: YAG, CTH: YAG,Er:YAG, Ho:YAG, Yb:YAG, Undoped YAG and so on, with the maximal diameter of 4-6 inches, as well large-size magneto-optical single crystal TGG and TSAG . And our company also can provide the various special crystal rods, large-size and high-concentration laser crystal slab, crystal substrates, and other special products under the requirements of the customers.
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. Cesium lithium borate generates the 4th and 5th harmonics of the Nd:YAG 1064 nm fundamental wavelength. A green laser pointer is a frequency doubled Nd:YVO4 diode-pumped solid state laser (DPSS laser). 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.
What is ND YAG laser used for? Nd:YAG lasers are used in ophthalmology to correct posterior capsular opacification, a condition that may occur after cataract surgery, and for peripheral iridotomy in patients with acute angle-closure glaucoma, where it has superseded surgical iridectomy.
What does ND YAG mean? Neodymium-doped yttrium aluminium garnet, Nd:YAG (neodymium-doped yttrium aluminium garnet) is a crystal that is used as a laser medium for solid-state lasers.
Is ND YAG laser effective? Conclusion The long-pulsed 1064-nm Nd:YAG laser is a safe and effective method of long-term hair reduction in patients with darkly pigmented skin.
Which laser is best for hair removal? The type of laser not only influences how well it works, it influences your chance of side-effects. Lasers suitable for hair removal include: long-pulse ruby lasers, long-pulsealexandrite lasers, long pulse diode lasers and long-pulse Nd:YAG lasers
What is YAG laser for face? The YAG laser is a kind of cosmetic laser commonly used for anti-aging skin treatments. It is considered “non-ablative,” meaning it penetrates the skin surface, and your skin tissue absorbs the energy.
Which is better Nd YAG or diode? The diode laser is most effective for darker terminal hair and is less effective on lighter, finer hair. ... It is an effective laser with more depth of penetration in comparison to IPL and Nd:YAG lasers. It exerts effect on the hair follicle by applying the principle of selective photothermolysis.
What is ND YAG laser hair removal? ND:YAG Laser Hair Removal is a highly effective and safe method of hair removal, we use the latest technology in Lasers to permanently reduce hair from the body and face. The majority of our clients have experienced amazing results. The length of a treatment time depends on the size of the area being treated.
Is ND YAG laser hair removal permanent? There were no permanent side effects despite one small scar after a folliculitis. Conclusions: The long pulsed Nd:YAG is suitable to remove hair for more than 12 months effectively, although 4-5 sessions are necessary for these results. Blond hair can also be removed, although much less effective.