Cr4+:YAG crystals Chromium Doped Yttrium AIuminum Garnet

Co2+:MgAl2O4 Cospinel is a relatively new material for passive Q-switching in lasers emitting from 1.2 to 1.6 μm, in particular, for eye-safe 1.54 μm Er:glass laser, but also works at 1.44 μm and 1.34 μm wavelengths. Spinel is a hard, stable crystal that polishes well. Cobalt substitutes readily for magnesium in the Spinel host without the need for additional charge compensation ions. High absorption cross section (3.5×10-19 cm2) permits Q-switching of Er:glass laser without intracavity focusing both with flash-lamp and diode-laser pumping. Negligible excited-state absorption results in high contrast of Q-switch, i.e. the ratio of initial (small signal) to saturated absorption is higher than 10.

Nd:YAG is the earliest and most famous laser host crystal. Since it combines great advantages in many basic properties,Nd:YAG is the ubiquitous presence for near-infrared solid-state lasers and their frequency-doubler, tripler, and higher order multiplier. It is widely used in industrial, medical, military and scientific fields.. Nd:YAG crystals are wildly used in all types of solid-state laser systems-frequency-doubled continuous wave, high-energy Q-switched, and so forth.Its good fluorescent lifetime thermal conductivity and physical strengths makes it suitable for high power lamp pumped laser.

Ti:Sapphire crystal is the most widely used tunable solid-state laser material combining the supreme physical and optical properties with the extremely broad lasing range. Its lasing bandwidth can support pulses < 10fs making it the crystal of choice for femtosecond mode-locked oscillators and amplifiers. The absorption band of Ti:Sapphire centers at ~ 490 nm so it may be conveniently pumped by various laser sources such as argon ion lasers or frequency doubled Nd:YAG, Nd:YLF, Nd:YVO4 lasers at ~530nm. Laser designers are using Ti:sapphire to generate femtosecond pulses to create new industrial tools. A properly delivered femtosecond laser pulse interacts within the target leaving the surrounding area undisturbed. Newly developed femtosecond pulsed lasers micro-machine complex fine structures in glass, metal and other materials. Active waveguides can be written below the surface, integrating optical devices within the body of a substrate. Defects in photomasks can be repaired without disturbing neighbouring patterns. And it is now possible to achieve cellular resolution in vivo for medical diagnosis with femtosecond pulse lasers.

CaF2 or Calcium Fluoride is a cubic crystal with an excellent transmission from 130 nm to 10 μm and has widespread applications as transparent windows in the ultraviolet and infrared spectra.

HGO grows BBO Nonlinear crystals using flux technology. BBO crystal transparency ranges from 188 nm to 5,2 µm, which includes reasonable transparency from 3-5,2 µm for few tens µm thick crystals, while their phase-matchable range spans almost over the entire transparency range. Combined with other magnificent properties of BBO, it is favorable for numerous nonlinear parametric applications. It is worth to mention that BBO crystals have the highest nonlinearity in the UV range out of all common nonlinear crystals.

Potassium Gadolinium Tungstate (KGd(WO₄)₂) crystal is an excellent stimulated Raman laser crystal with characteristics such as a wide light transmission range, good thermal conductivity, high damage threshold, large Raman shift coefficient, and high Raman gain. It can maintain high conversion efficiency and beam quality during the Raman frequency conversion process. The KGW crystal can withstand high pump power and is suitable for pump lights of various wavelengths, making it widely used in Raman lasers, laser frequency conversion, medical imaging, photodynamic therapy, environmental monitoring, spectroscopy research, material processing, and other fields.

A band pass filter is a device that passes frequencies within a certain range and rejects (attenuates) frequencies outside that range, and it’s used to selectively transmit a portion of the spectrum while rejecting all other wavelengths.

HGO grows Tm:YLF laser crystals using Czochralski technology. Tm:YLF is an important middle infrared laser crystal. Because Tm:YLF is negative uniaxial crystal, whose thermal refractive index coefficient is negative, some thermal distortion may be counteracted and high-quality light can be output. Conveniently pumped at 792nm, 1.9μm linearly polarized beam is output in a axis, and non-linearly polarized beam is output in c axis. The YLF crystals has low non-linear refraction index value and thermo optical constants, which makes these crystals applicable in research, development, education, production, photonics, optic, laser technology and telecommunications. Besides, Tm3+:YLF lasers are ideal pump sources for 2.1 μm Ho3+:YAG lasers. This is due to a good overlap of Tm3+:YLF emission and Ho3+:YAG absorption spectra and the capacity of producing linearly polarized output. What is more, the refractive index of Tm3+:YLF decreases with temperature, leading to a negative thermal lens that is partly compensated by a positive lens effect due to end face bulging.