Optical crystals are transparent in different spectral regions, depending upon the crystal material. Optical crystals include nonlinear crystals, photorefractive crystals, laser crystals, acousto-optic and electro-optic combinations, X-ray analysis crystals, scintillation crystals, and different types of crystals that are used in semiconductors.

Optical crystals are used mainly in laser applications. A nonlinear optical crystal is used as a frequency converter in a laser and includes a crystal composed of substances such as lithium niobate, barium borate, lithium triborate, and potassium titanyl phosphate. Each of these optical crystals has specific operating characteristics and should be selected based on the laser application. For example, a lithium niobate crystal may be used to as a frequency doubler in an optical parametric oscillator (OPO) device. A nonlinear optical crystal is often used in an Nd:YAG laser. An Nd: YAG laser is a system that uses neodymium-doped (Nd) yttrium aluminum garnet crystals. An Nd:YAG crystal is one of the most common optical crystals and is used in solid-state lasers for a wide variety of applications. The amount of neodymium used to dope the YAG crystal depends on its use. For use in pulsed lasers, the crystal has a higher doping than in continuous use lasers.

Optical crystals are transparent in different spectral regions, depending upon the crystal material. Optical crystals include nonlinear crystals, photorefractive crystals, laser crystals, acousto-optic and electro-optic combinations, X-ray analysis crystals, scintillation crystals, and different types of crystals that are used in semiconductors.

Optical crystals are used mainly in laser applications. A nonlinear optical crystal is used as a frequency converter in a laser and includes a crystal composed of substances such as lithium niobate, barium borate, lithium triborate, and potassium titanyl phosphate. Each of these optical crystals has specific operating characteristics and should be selected based on the laser application. For example, a lithium niobate crystal may be used to as a frequency doubler in an optical parametric oscillator (OPO) device. A nonlinear optical crystal is often used in an Nd:YAG laser. An Nd: YAG laser is a system that uses neodymium-doped (Nd) yttrium aluminum garnet crystals. An Nd:YAG crystal is one of the most common optical crystals and is used in solid-state lasers for a wide variety of applications. The amount of neodymium used to dope the YAG crystal depends on its use. For use in pulsed lasers, the crystal has a higher doping than in continuous use lasers.

Optical crystals can be used in many different infrared (IR) laser applications. An infrared optical crystal or IR optical crystal such as sodium iodide or germanium is used in scintillation detectors and gas analyzers. Infrared optical crystals are also widely used in military infrared optical devices. Other optical crystal materials include sapphires, which are chosen for their optical transmission and low wavefront distortion characteristics. Crystal sapphire optical components are used in high power laser windows. Some optical crystals are clear or colorless. An acousto-optical crystal such as tellurium dioxide is a clear optical crystal that can be used in argon laser applications.