ANNEALING OF THIN-FILM COATINGS OF VANADIUM OXIDE ON THE SURFACE OF FIBER LIGHT GUIDES

A method for controlled annealing of thin-film vanadium oxide coatings on the surface of quartz optical fibers is demonstrated. Thin-film coatings were obtained on a chemically thinned optical fiber surface using the method of chemical vapor deposition from organometallic compounds using vanadyl isopropoxide. It is shown that in an inert atmosphere, thin-film amorphous coatings consist mainly of a mixture of V2O5 and V6O13, which is confirmed by Raman spectra. Coatings annealed in a reducing environment demonstrate a second-order phase transition near room temperature (~65 ℃). Annealing was carried out at temperatures from 225 to 420 ℃ with process control using the transmission spectrum of the optical path.