Control of Photonic Spectrum of a Bragg Microresonator with a Magnetoactive Layer

Transmission spectra of a microresonator structure with Bragg mirrors are obtained. A quarter-wave plate made of extrinsic semiconductor is installed in the working cavity. The properties of such a semiconductor can be controlled using external magnetic field. It is shown that variations in the external field, cavity size, and position of the active layer lead to modification of the photonic spectrum of the TM and TE eigenwaves. Splitting of a defect mode at the center of the band gap into two modes takes place when the active layer is placed in the cavity. The evolution of such modes caused by variations in the magnetic field is studied. Dependences of the size and number of stopbands on the structural parameters, frequency, and field are determined, and maps of band gaps are obtained.