Dielectric optical interference coatings on glass and elements of laser systems (Ultraviolet – visible – Infrared IR region of the spectrum)
In recent years, JSC Polyus Research Institute by M.F.Stelmakh has been working on developing new coatings and improving well-known one to meet the requirements applied to laser technology and microelectronics. During this time, technological equipment intended for the deposition of dielectric interference coatings has been significantly upgraded. The coatings deposition is performed according to specially developed programs that allow the computer technology to be successfully used in technological processes.
The recent use of ion-assisted deposition in combination with ion-beam cleaning of the surface of the deposed materials has significantly improved the surface morphology of film coatings and its structure. It allowed reducing the absorption in the films deposition and increasing the radiation strength.
Below there are interference coatings that can be used in various lasers and devices based on lasers. It is also possible to develop special coatings that can be applied to the specified spectrum ranges.
Anti-reflection coatings of optical materials and crystals are applied at a certain wavelength in the spectral range of 193-3200 nm
It is possible to apply anti-reflection coatings in the medium and long IR regions (Ge, Si, ZnSe). Anti-reflection of water-soluble crystals.
Anti-reflection coatings of optical materials and crystals can be made at two and three wavelengths
Achromatic and broadband anti-reflection coatings
Beam splitting coatings
Beam splitting coatings used for UV, visible and infrared spectra spectrum ranges at different angles of incidence and polarization. Coatings can be deposited on prisms used for beam splitting cubes. Different ratios of reflected and transmitted radiation are possible both for a certain wavelength and for the spectral range.
Partially reflective coatings
Partially reflective coatings are used as an optical element of the laser resonator. The coating can be manufactured for all major radiation generation lengths. Also the coating can be manufactured according to special requirements. The standard tolerance to the main reflectance value is ±2%. For the reflectance value of R > 98-99%, the tolerance is ±0.3%.
Parametric coatings are used for various wavelengths, as well as spectral ranges.
The radiation incident angle on the optical detail is 0°-70°. In this case, the polarization of reflected and transmitted radiation may be different.
Highly reflective coatings
Highly reflective coatings provide reflection of R > 99.8-99.9% for certain wavelengths in the 0.19-3.5 µm spectral range, and for spectral ranges (broadband reflective coatings).
The coatings can be manufactured for different angles of incidence and radiation polarization.
Interference polarizers can be considered as one of the main elements of lasers. Depending on the operating conditions polarizers can be 70°±2°, 45°, 55°±2°.
Interference polarizers can be manufactured for a particular wavelength in the ultraviolet - visible - near infrared spectral range. Polarizer contrast TP:TS > 3000:1. Laser strength — 1 GW/cm2, 10 ns, 20 Hz for a wavelength of 1064 nm. It is possible to design polarizing cube (see beam-splitting coatings).
Interference light filters
The interference filters can be manufactured as elementary filters that selectively emit a certain wavelength, or using a barrier region in a certain spectral range.