Medicine Slit lamp photograph of posterior capsular opacification visible a few months after implantation of intraocular lens in eye, seen on retroillumination<unk> s are used in ophthalmology to correct posterior capsular opacification, after cataract surgery, for peripheral iridotomy in patients with chronic and acute angle-closure glaucoma, where it has largely superseded surgical iridectomy, for the treatment of vitreous eye floaters, for pan-retinal photocoagulation in the treatment of proliferative diabetic retinopathy, and to damage the retina in ophthalmology animal research.<unk> s 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,<unk> s 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),<unk> s 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.<unk> s are also used to treat Venous Lake lip lesions. Recently<unk> s have been used for treating dissecting cellulitis of the scalp, a rare skin disease. Using hysteroscopy the<unk>  has been used for removal of uterine septa within the inside of the uterus. In podiatry, the<unk>  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. Dentistry<unk> :YAG dental lasers have been used for the removal of dental carries as an alternative to drill therapy, although evidence supporting its use is of low quality. They have also been used for soft tissue surgeries in the oral cavity, such as gingivectomy, periodontal sulcular debridement, LANAP, and pulpotomy.<unk> :YAG dental lasers have also been shown to be effective at treating and preventing dental hypersensitivity, as an adjunct for periodontal instrumentation, and for the treatment of recurrent aphthous stomatitis. Manufacturing<unk> s 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<unk> s (millisecond pulses, not Q-switched).<unk> s 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.<unk> s 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<unk> s can be used for flow visualization techniques in fluid dynamics (for example particle image velocimetry or laser-induced fluorescence). Biophysics<unk> s are frequently used to build optical tweezers for biological applications. This is because<unk> s 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<unk>  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<unk>  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<unk>  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<unk>  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<unk> :YAG is thought to be particularly dangerous, as it is invisible and initial exposure is painless. 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. Cavity ring-down spectroscopy (CRDS) The<unk> :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<unk> s 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<unk>  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<unk> s, 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.
Nd:YAG laser
Carbon-dioxide laser
Laser
GreenLight Laser Therapy
Laser surgery
Laser coagulation
Laser hair removal
Low-level laser therapy