Design And Fabrication Of Polarizer Based On All-Dielectric Resonance-Domain Grating

Based on the characteristics of resonance-domain grating, a high performance polarizer for near-infrared communication band is designed and fabricated using commercial silicon-on-insulator(SOB. In the wavelength range of 1.460 mu m to 1.625 mu m, an all-dielectric resonance-domain grating with a period of 0.98 mu m is designed by use of finite difference time domain method. The maximum extinction ratio of the grating is up to 55 dB. According to the results of the design, the polarization grating is experimentally fabricated by electron beam lithography and the polarization performance of grating is measured. Experimental results show that the transmission of transverse magnetic polarized light of grating exceeds 80%, the extinction ratio of the polarization grating is more than 20 dB, and the maximum value can reach up to 32 dB, agreeing well with the simulation results. Compared with the polarization characteristics of the traditional sub-wavelength metal grating whose period requires less than a quarter of the incident light wavelength, the polarization grating exhibits good polarization performance with near wavelength grating period, reducing the difficulty of lithography in fabrication. Moreover, the polarizer is fabricated based on commercial SOI, which is compatible with the existing mature semiconductor technology and has strong integration and practicability.