Crystals and optics processing services

Waveplates (retardation plates or phase shifters) are made from materials which exhibit birefringence. The velocities of the extraordinary and ordinary rays through the birefringent material varies inversely with their refractive indices. This difference in velocities gives rise to a phase difference when the two beams recombine.

HGO grows Pr:YLF laser crystals using Czochralski technology. Pr3+:YLF has been found as promising laser material for producing visible lasers directly and UV lasers through intracavity second-harmonic generation. Very few laser materials have the necessary properties for the realization of lasing in the visible spectral range. Trivalent praseodymium (Pr3+) is known to be an interesting laser ion for use with solid-state lasers in the visible spectral range because of its energy levels scheme, providing several transitions in the red (640 nm, 3P0 to 3F2), orange (607 nm, 3P0 to 3H6), green (523 nm, 3P0 to 3H5), and dark red (720 nm, 3P0 3F3+3F4) spectral regions.

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.

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.

Magnesium Fluoride Windows applicable for wide range spectrum, transmits well into the VUV region at the hydrogen Lyman-alpha line and beyond and it is particularly useful for Excimer laser application.It is resistant to mechanical and thermal shock, to radiation, and is chemically stable.    

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.

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.

A Plano-Convex lens causes light to focus to a point,it has a positive focal length,which is ideal for light collimation or for focusing applications utilizing monochromatic illumination, in a range of industries. HG OPTRONICS offers Plano-Convexlenses with a variety of coating options.