TGG crystal Terbium Gallium Garnet

The Yttrium Orthovanadate (YVO4) is a positive uniaxial crystal grown with Czochralski method. It has good temperature stability and physical and mechanical properties. It is ideal for optical polarizing components because of its wide transparency range and large birefringence. It is an excellent synthetic substitute for Calcite (CaCO3) and Rutile (TiO2) crystals in many applications including fiber optic isolators and circulators, interleavers, beam displacers and other polarizing optics.

LiNbO3 is widely used as electro-optic modulators and Q-switches for Nd:YAG, Nd:YLF and Ti:Sapphire lasers as well as modulators for fiber optics.

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.

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.

Er3+, Yb3+ co-doped phosphate glass is a well-known and commonly used active medium for lasers emitting in the “eye-safe” spectral range of 1,5-1,6 µm. As an eye-safe wavelength laser, 1540um ,Er3+/Yb3+ co-doped phosphate glass lasers have attracted much attention for their compactness and low cost, such as laser generation and signal amplification because the wavelength of 1540nm is just at the position of the eye-safe and the fiber optic communication window. 1540nm lasers have used in ranging finder, radar, target recognition. Er3+/Yb3+ co-doped phosphate glass cooperate with passive Q-Switch crystal cospinel can get 1540nm pulse solid-state 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.

HGO grows Ho:YLF laser crystals using Czochralski technology. Ho:YLF is a very attractive laser material, because the lifetime of the upper laser level is much longer ( ~ 14 ms) than in Ho:YAG and the emission cross sections are higher. Additionally the thermal lens in Ho:YLF is much weaker, which helps to generate diffraction limited beams even under intense end-pumping. The primary advantage of directly pumping the Ho 5I7 is that it does not have to depend on energy transfer, which lends itself to various radiative and non-radiative losses. Up-conversion losses that have deleterious effect in high-energy Q-switched lasers are eliminated.

Cr4+:YAG (Y3Al5O12) crystal is ideal for passive Q-switch operation of Nd:YAG and other Nd3+ or Yb3+ doped laser crystals in the wavelength range of 900 nm to 1200 nm. Passive Q-switches or saturable absorbers provide high power laser pulses without electro-optic Q-switches, thereby reducing the package size and eliminating a high voltage power supply. A remarkable feature of Cr4+:YAG is the high damage threshold of >10 J/cm2@1064 nm, 10 ns. Its absorption band extends from 900 nm to 1200 nm and peaks around 1060 nm with a very large absorption cross-section.