Diffusion Bonded Crystals with High Damage Threshold

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.

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.

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.

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.

Double Concave Lenses are used in beam expansion, image reduction, or light projection applications. These lenses are also ideal for expanding the focal length of an optical system. Double Concave Lenses, which have two concave surfaces, are Optical Lenses with negative focal lengths. HG OPTRONICS offers Double Concave lenses with a variety of coating options.

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.

In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. At least two of the flat surfaces must have an angle between them. The exact angles between the surfaces depend on the application. The traditional geometrical shape is that of a triangular prism with a triangular base and rectangular sides, and in colloquial use "prism" usually refers to this type. Some types of optical prism are not in fact in the shape of geometric prisms. Prisms can be made from any material that is transparent to the wavelengths for which they are designed.

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.