Broadband power filters based on Bragg mirrors with alternating phase change material

We explore the transport properties of a composite periodic photonic structure consisting of two Bragg mirrors with layers of the same optical length but different material. Specifically, we assume that the second mirror involves alternating layers made of a phase change material (PCM). When the incident electromagnetic radiation is low the two Bragg mirrors share the same pass-band characteristics and thus the whole structure demonstrates the same transport properties as the ones associated with the individual mirrors. When, however, the incident electromagnetic radiation is above some critical value, the permittivity of the PCM layers change considerably leading to a shift of the pass-bands of the second mirror. As a result, we observe the development of multiple gaps inside the pass-bands of the initial composite structure. This self-induced broad band suppression of transport in the case of high power EM waves might be useful for the realization of broad-band power filters.