Surface polaritons in single-crystal and polycrystalline samples of BeO

An investigation was made of the infrared reflection spectra and of the frustrated total internal reflection spectra of single-crystal and polycrystalline samples of BeO, which is a promising material for quantum-electronic devices operating in the middle infrared range. It was found that "resonance" dips in the infrared reflection spectra of these materials observed in the frequency range of CO₂ laser radiation are due to excitation of surface polaritons. An analysis was made of the possibility of using surface periodic structures in BeO, formed as a result of interference of the incident laser radiation and surface polaritons, as frequency-selective components of resonators in CO₂ waveguide lasers.