Crystals and optics processing services

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.

A Neutral Density filter allows a photographer to control the exposure in an image very easily. The filter stops light reaching the camera sensor, therefore allowing us to leave the camera with a higher aperture for a longer amount of time. HG OPTRONICS neutral-density filter is a filter that reduces or modifies the intensity of all wavelengths, or colors, of light equally, giving no changes in hue of color rendition.

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.

Fused silica window, with low thermal expansion,  providing stability and resistance to thermal shock over large temperature excursions, wide thermal operating range and high laser damage threshold, is a better choice for transmission from UV to IR.

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.

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.

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.

Plano-concave rectangular cylindrical lenses provide uni- axial negative imaging for anamorphic beam expansion and a wide range of applications.These lenses may also be used as mirror blanks if a concave cylindrical surface mirror is required.