Creation of the cavity of the tunable whispering gallery modes mid infrared laser

The technology of fabrication disk cavity of whispering gallery modes (WGM) laser for middle Infrared (MIR) spectral range was developed. The post-growth geometry formation of the disk cavity was performed using selective wet chemical etchant comprised of CrO₃, HF and H₂O. The wet-chemical etchant for semiconductor multilayers heterostructures lattice-matched to GaSb was investigated. The application of this technology allow us to fabricate the disk cavity with a diameter of 200 ¿m and height 15 ¿m. To enlarge the optical power of emission the disk chip was cleaved up to symmetric half-disk. It was established, that the lasers assembled on the basis of such half-disk cavity are tunable and generate at the wavelength of 2.35 ¿m at 300 K.