CaF2 crystal Calcium Fluoride windows

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.

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.

Pure YAG Yttrium Aluminum Garnet is a new substrate and window material that can be used for both UV and IR optics. It is particularly useful for high-temperature and high-energy applications. The mechanical and chemical stability of YAG is comparable to sapphire crystal, but YAG is unique with no birefringence which is extremely important for some optical applications.

IPL Filter is the key optical element for IPL (intense Pulsed Light) machine, which blocks the UV wave and transmits the useful wave from 400nm to 1200nm for laser equipment, such as photo-rejuvenation hair removal, vascular and acne treatment, skin rejuvenation.

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.

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.

Germanium (Ge) is the preferred lens and window material for high performance infrared imaging systems in the 8–12 um wavelength band.

Nd:YVO4 (Neodymium Doped Yttrium Orthovanadate) crystals is one of the most promising commercially available diode pumped solid state laser materials, especially, for low to middle power density. This is mainly for its higher absorption and emission features than Nd:YAG crystal. Pumped by laser diodes, Nd:YVO4 crystal has been incorporated with high NLO coefficient crystals ( LBO, BBO, or KTP) to frequency-shift the output from the near infrared to green, blue, or even UV. This incorporation to construct all solid state lasers is an ideal laser tool that can cover the most widespread applications of lasers, including machining, material processing, spectroscopy, wafer inspection, light displays, medical diagnostics, laser printing, and data storage, etc. It has been shown that Nd:YVO4 based diode pumped solid state lasers are rapidly occupying the markets traditionally dominated by water-cooled ion lasers and lamp-pumped lasers, especially when compact design and single-longitudinal-mode outputs are required.