The AMO group as a part of the Laboratory for Attosecond Physics has for the first time designed and produced Complementary pair of dispersive multilayers operating in the 2-4 µm spectral range. The mirrors comprise layers of Si and SiO2 thin-film materials. The pair exhibits unparalleled reflectance exceeding 99.7% and provides a group delay dispersion of (-200) fs2. The mirrors can be used in Cr:ZnS/Cr:ZnSe femtosecond lasers and amplifiers.
Our motivation for developing these Complementary pair of dispersive multilayers was the fact that Novel 2.4-µm chromium doped zinc sulfide (Cr:ZnS) high-power lasers are being developed at the Laboratory of Attosecond Physics. The lasers will extend laser output to 3.2 µm. Dispersive mirrors are key elements of these lasers. In order design and produce dispersive mirrors suitable for the spectral region 2-4 µm, Si/SiO2 materials pair was proposed. The combination Si/SiO2 exhibits a high refractive index ratio and allows one to produce broadband dispersive mirrors.
Original publication:»Complementary Si/SiO2 dispersive mirrors for 2-4 µm spectral range« (Optics Express 27, 34901 (2019))