Investigation of Optical Resonators and Band-Pass Filters on Structures Made of Alternating Layers of Quartz and Silver

https://doi.org/10.1134/S0030400X25700092

The characteristics of a planar optical resonator made of quartz glass surrounded by silver mirrors have been studied when their thickness was varied. The frequency responses of band-pass filters on planar structures obtained by vacuum deposition on quartz glass (SiO₂) substrates of three quartz layers, which are half-wavelength resonators separated from each other, from the substrate, and from the free space by four layers of silver (Ag), were measured. The thicknesses of the Ag and SiO₂ layers were determined on the basis of the specified filter passband parameters by synthesizing one-dimensional models using electrodynamic analysis. The experimental frequency dependencies of the real and imaginary parts of the complex permittivity of silver have been considered. The measured frequency responses of the manufactured prototypes of red, green, and violet filters are in good agreement with the characteristics obtained during synthesis. Systematic studies of filters with a central passband frequency of 300 THz (wavelength of 1 µm) and a relative bandwidth of 2‒20%, containing from 3 to 6 resonators, have been carried out. The high performance of the developed filters demonstrates their potential for their use in optical devices.