Hyperuniform disordered photonic bandgap polarizers

Abstract

An ultra-broadband transverse magnetic (TM) pass hyperuniform disordered photonic bandgap (HUDPBG) polarizer based on disordered air holes is proposed and demonstrated on a silicon-on-insulator platform. The transverse electric mode is blocked by the combination of three effects: the photonic bandgap (PBG) effect, diffusive (nonresonant) scattering, and band edge resonances. Specifically, the designed bandwidth of 265 nm for a 30-dB polarization extinction ratio (PER) is much larger than the spectral width of the PBG (149 nm) because of the band edge resonances. The TM mode is in the subwavelength regime of the hyperuniform disordered photonic structure and thus has a low insertion loss (IL). An ultrawide bandwidth of 210 nm (1.44–1.65 μm) for the 30-dB PER is experimentally demonstrated in a 12.9-μm-long HUDPBG polarizer. The spectrally averaged PER is 39.6 dB, and the IL for the TM mode is 1.1 dB (IL = 0.6 dB at 1.55 μm). The HUDPBG polarizers based on the disordered air holes can be an excellent candidate for ultra-broadband polarization filtering in the silicon photonic platform.