Crystals and optics processing services

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.

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.

Penta Prisms are used to define right angles in optical systems. Penta Prisms, which provide right handed images,feature a ray deviation of 90°. Penta Prisms are five-sided prisms are unaffected by slight movements. HG OPTRONICS offers a variety of Penta Prisms for optimal performance in the Ultraviolet (UV), Visible, or Infrared (IR) spectrums.  

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.

Longpass filters are ideal for a variety of applications, such as gas monitoring, temperature, sensing, thermal imaging and motion sensing, etc. Longpass filters block shorter wavelengths and transmit longer wavelengths. Blocking can be from reflectance, absorption or a combination. Transmission in the pass band can be enhanced with an antireflection coating on the second surface.

Silicon is used as an optical window primarily in the 3 to 5 micron band and as a subsrate for production of optical filters and windows.     Silicon (Si) is grown by Czochralski pulling techniques (CZ) and contains some oxygen that causes an absorption band at 9 microns. To avoid this, material can be prepared by a Float-Zone (FZ) process. Optical silicon is generally lightly doped (5 to 40 ohm cm) for best transmission above 10 microns, and doping is usually boron (P-type) and phosphorus (N-type). After doping silicon has a further pass band: 30 to 100 microns which is effective only in very high resistivity uncompensated material.    

Er3+, Yb3+ co-doped phosphate glass is a well-known and commonly used active medium for lasers emitting in the “eye-safe” spectral range of 1,5-1,6 µm. As an eye-safe wavelength laser, 1540um ,Er3+/Yb3+ co-doped phosphate glass lasers have attracted much attention for their compactness and low cost, such as laser generation and signal amplification because the wavelength of 1540nm is just at the position of the eye-safe and the fiber optic communication window. 1540nm lasers have used in ranging finder, radar, target recognition. Er3+/Yb3+ co-doped phosphate glass cooperate with passive Q-Switch crystal cospinel can get 1540nm pulse solid-state laser.

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.