A Monolithic CMOS Image Sensor With Wire-Grid Polarizer Filter Mosaic in the Focal Plane

作者：Zhang Milin^*; Wu Xiaotie; Engheta Nader; Van der Spiegel Jan

来源：IEEE Transactions on Electron Devices, 2014, 61(3): 855-862.

DOI：10.1109/TED.2014.2299757

• Metallic gratings
• polarimetry
• polarization sensitive image sensor

In this paper, we report on an image sensor with an integrated focal-plane 2x2 wire-grid polarizer for the visible spectrum, fabricated in a 65-nm standard CMOS technology. This imager enables the reconstruction of the polarization response for each pixel. Finite-difference time-domain method has been used to optimize the extinction ratio (ER) in the visible spectrum of a multilayered focal-plane wire-grid polarizer. Experimental results show that an ER of 16.35 dB is achieved with a standard error of similar to 0.25% between the experimental results and the fitting sinusoidal polarization response curve. Design guidelines for the wire-grid polarizer are derived based on numerical analysis and experimental results. Sensitivity ratio is defined to balance the tradeoff between the intensity sensitivity and polarization sensitivity of the imager.

• 出版日期2014-3