Reconfigurable and dual-polarization Bragg grating filter with phase change materials

Fully reconfigurable optical filters are indispensable building blocks to realize reconfigurable photonic networks/systems. This paper proposes a reconfigurable and dual-polarization optical filter based on a subwavelength grating waveguide operating in the Bragg reflection mechanism and combined with a low-loss phase change material Ge2Sb2Se4Te1. Numerical simulations indicate that, for TE(TM) polarization, the presented Bragg grating filter offers up to 20 nm (17 nm) redshift with amplitude modulation of 6 dB (0.15 dB) at 1550 nm. Using the effective medium theory, we obtained the six-level crystallization performance of the optical filter. The proposed optical filter has potential applications in wavelength-division-multiplexing systems, optical signal processing, and optical communications.