Electron Beam Lithographic Pixelated Micropolarizer Array for Real-Time Phase Measurement

Pixelated micropolarizer arrays (PMAs) have recently been used as key components to achieve real-time phase measurement. PMA fabrication by electron beam lithography and inductively coupled plasma-reactive ion etching is proposed in this work. A 320×240 aluminum PMA with 7.4 μm pitch is successfully fabricated by the proposed technique. The period of the grating is 140 nm, and the polarization directions of each of the 2×2 units are 0°, 45°, 90°, and 135°. The scanning electron microscopy and optical microscopy results show that the PMA has a good surface characteristic and polarization performances. When the PMA is applied to phase-shifting interferometry, four fringe patterns of different polarization directions are obtained from only one single frame image, and then the object wave phase is calculated in real time.