Design and fabrication of As2S3-based non-quarterwave multi-cavity Fabry-Perot filters with the laser-adjustable central wavelength

Opt Lett. 2022 Sep 1;47(17):4407-4410. doi: 10.1364/OL.471421.

Abstract

We present a thorough study of the use of As2S3 thin films for the fabrication of high-performance multi-cavity bandpass filters. We show that such layers can be used inside a non-quarterwave multi-cavity Fabry-Perot structure to produce local changes of the central wavelength of the filter using photosensitive properties of this material. In particular, we study the impact of these index changes on the spectral performances of the filters and show how to adapt the design of the Fabry-Perot structures to produce a spectral shift without degrading the bandpass profile. Double- and three-cavity Fabry-Perot filters are theoretically and experimentally studied.