The development of Cs3Sb transmissive interference cathode technology needs processing of such photocathodes on thin dielectric films coated on glass substrates, Here the use of such films as light resonators is made for reducing the light losses due to reflection at the cathode surface. Consequently the sensitivity of the photoeathode is enhanced. TiO2 and SiO films are chosen for their good optical properties with Cs3Sb photocathodes in interference photoemission. Deposition methods and instrumentation in assessing their properties are discussed.