Polarizing beam splitter is designed with a broadband and wide range of incident angle. Polarizing beam splitter designed here is a kind of double periodic subwavelength medium-metal grating, which consisted of silicon dioxide as the substrate, magnesium fluoride (MgF2) as medium material and silver for the grid lines. It has the polarization splitting function of TE reflection and TM transmission. Based on the rigorous coupled-wave analysis(RCWA) and the continuous optimization of the structure parameters, the polarization beam splitter has high polarization conversion efficiency, high extinction ratio and a wide tolerance of incident angle in the near infrared band (1μm − 3μm) .The simulation results show that the reflection efficiency of TE polarized light and the transmission efficiency of TM polarized light are both higher than 96%, and the reflection extinction ratio and transmission extinction ratio are greater than 17dB and 28dB respectively. When the incident angle of incident light is from -80° to 80°, the reflection efficiency of TE polarized light is over 96%; when the incident angle is from -40°to 40°, the transmission efficiency of TM polarized light is over 90%. The reflection extinction ratio exceeds 17dB, and the transmission extinction ratio exceeds 35dB in the incident wavelength of 1550nm.The designed polarizing beam splitter is expected to be used in optical communication, optical storage, optical sensing and other fields for light modulation and control.
We introduce phase-change material Ge2Sb2Te5 (GST) into metal–insulator–metal (MIM) waveguide systems to realize chipscale plasmonic modulators and switches in the telecommunication band. Benefitting from the high contrast of optical properties between amorphous and crystalline GST, the three proposed structures can act as reconfigurable and nonvolatile modulators and switches with excellent modulation depth 14 dB and fast response time in subnanosecond while possessing small footprints, simple frameworks, and easy fabrication. We provide solutions to design active devices in MIM waveguide systems and can find potential applications in more compact all-optical circuits for information processing and storage.