Crystals and optics processing services

Calcium Fluoride windows and lenses for UV and IR spectrum. Custom made CaF2 windows, CaF2 lenses and wedges according to customer's specifications. CaF2 windows up to 220mm diameter; CaF2 wedges, prisms and CaF2 mirrors; Excimer CaF2 optics, Raman grade CaF2 optics and etc.

BK7 window is the most common type of window. It has good performance over visible and near infrared wavelength regions. At the same time, BK7 window is ideal for applications require minimal transmitted beam deviation. It is suitable for AR coating.

MgF2 or Magnesium Fluoride is positive uni-axial crystal with a very high optical transmittance from the vacuum UV to IR. It is regularly used for optical elements where extreme ruggedness and durability is required. It also has a large resistance to mechanical and thermal shock, to optical radiation, and is chemically stable, making it a very useful materials for UV and IR optics.

Diffusion bonded crystals consist of one laser crystal and one or two undoped material. They are combined by optical contact method and further bonded under high temperature. Diffusion Bonded Crystal helps to decrease thermal lens effect considerably of laser crystals, provides integral components to make compact lasers. HGO are able to supply various standard assembly and special customized bonding crystals.These diffusion bonded composite crystals have different wedge structures, Brewster angles, etc. It is used to effectively reduce the thermal effect of solid-state high-power lasers.

KDP Potassium Dihydrogen Phosphate and KD*P or DKDP Potassium Dideuterium Phosphate are among the most widely-used commercial NLO materials, characterized by good UV transmission, high damage threshold, and high birefringence, though their NLO coefficients are relatively low. They are usually used for doubling, tripling and quadrupling of a Nd:YAG laser under the room temperature. In addition, they are also excellent electro-optic crystals with high electro-optic coefficients, widely used as electro-optical modulators, such as Q-switches, Pockels Cells, etc.

Silicon is used as an optical window primarily in the 3 to 5 micron band and as a subsrate for production of optical filters and windows.     Silicon (Si) is grown by Czochralski pulling techniques (CZ) and contains some oxygen that causes an absorption band at 9 microns. To avoid this, material can be prepared by a Float-Zone (FZ) process. Optical silicon is generally lightly doped (5 to 40 ohm cm) for best transmission above 10 microns, and doping is usually boron (P-type) and phosphorus (N-type). After doping silicon has a further pass band: 30 to 100 microns which is effective only in very high resistivity uncompensated material.    

Nd:GdVO4, is a promising material for diode pumped lasers. Similar to the more well-known Nd:YVO4 crystal, Nd:GdVO4 crystal also exhibits high gain, low threshold, and high absorption coefficients at pumping wavelengths. Nd:GdVO4 has the additional advantage over Nd:YVO4 of a much higher thermal conductivity. For CW lasing at 1.06 um and 1.34 um and intracavity doubling with KTP and LBO, the gadolinium vanadate have produced a higher slope efficiency or optical conversion than Nd:YVO4.

Ytterbium-doped Potassium Gadolinium Tungstate (Yb:KGd(WO₄)₂, Yb:KGW) crystal is an excellent laser gain material, boasting numerous advantages over the widely used Nd³⁺-doped materials. Its wide spectral emission band of 1023-1060 nm enables the generation of short laser pulses (picosecond or femtosecond level). The broad absorption band at 980 nm and highly absorbent pump radiation allow it to efficiently utilize diode laser pumping. Compared with YAG doped with Yb³⁺ ions, KGW crystal has a larger absorption cross-section, which reduces the minimum pump intensity required to achieve transparency in the quasi-two-level system of Yb.