Crystals and optics processing services

Double Convex Lenses are used in image relay applications, or for imaging objects at close conjugates. Double Convex Lenses have positive focal lengths, along with two convex surfaces with equal radii. Aberrations will increase as the conjugate ratios increase.  Double-Convex Lenses are used in a range of industries or applications. HG OPTRONICS offers Double Convex lenses with a variety of coating options.

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.

Plano-convex circular cylindrical lenses are useful for line imaging or uni-axial magnification in a wide range of applications. These lenses may be combined with other lenses to form complex imaging systems.

The dichroic mirror is a mirror with significantly different reflection or transmission properties at two different wavelengths, it’s characterized by almost complete transmission of light at certain wavelengths and almost complete reflection of light at other wavelengths. It can be widely used in Laser technology applications.

YbYAG crystal is more suitable for diode-pumping than the traditional Nd-doped systems. It can be pumped at 0.94 μm laser output. Compared with the commonly used Nd:YAG crystal, Yb:YAG crystal has a much larger absorption bandwidth to reduce thermal management requirements for diode lasers, a longer upper-state lifetime, three to four times lower thermal loading per unit pump power. Yb:YAG crystal is expected to replace Nd:YAG crystal for high power diode-pumped lasers and other potential applications.

α-BBO (α-BaB2O4) is a negative uniaxial crystal which has large birefringence over a broad transparent range of 190nm to 3500nm. α-BBO is an excellent crystal especially in UV and high power applications. The physical, chemical, thermal, and optical properties of alpha-BBO crystal are similar to those of Beta-BBO. However, there is no second order nonlinear effect in alpha-BBO crystal due to the centrosymmetry in its crystal structure and thus it has no use for second order nonlinear optical processes. Instead, alpha-BBO is widely used for fabrication of polarizers, polarizing beam displacers, phase retarders, birefringent plates, and time delay compensators especially those for UV and high power lasers.

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 LiF crystals in house using Czochralski technology. LiF crystal or lithium fluoride crystal is an optical material with outstanding transmittance in VUV region. It is also used for windows, prisms, and lenses in the visible and infrared in 0.104µm-7µm. LiF single crystal is sensitive to thermal shock and would be attacked by atmospheric moisture at 400°C. When working at a high temperature of 600°C, the LiF crystal softens and is slightly plastic, so it can be bent into radius plates. In addition irradiation produces color centers. Hence, users should take measures to protect LiF crystals from moisture and high energy radiation damages. What is more LiF can be cleaved along (100) plane and less commonly (110) plane. The optical characteristics are good and yet the structure is not perfect and cleavage is difficult.