Si metasurface half-wave plates demonstrated on a 12-inch CMOS platform

Half-wave plate (HWP) is one of the key polarization controlling devices in optical systems. The conventional HWPs based on birefringent crystals are inherently bulky and difficult to be monolithically integrated with other optical components. In this work, metasurface-based HWPs with high compactness are demonstrated on a 12-inch silicon complementary metal-oxide-semiconductor platform. Three-dimensional finite difference time domain simulation is used to design the nanostructure and investigate the impact of fabrication process variation on the device performance. In addition, the cross- and co-polarization transmittance (Tcross and Tco) of the HWPs located at different wafer locations are characterized experimentally. The peak Tcross and valley Tco values of 0.69 ± 0.053 and 0.032 ± 0.005 are realized at the wavelength around 1.7 μm, respectively. This corresponds to a polarization conversion efficiency of 95.6% ± 0.8%.