Fig. 3: Polarization conversion dynamics.
From: Full-range birefringence control with piezoelectric MEMS-based metasurfaces
a, b Optical images of the reflected light at the direct image (DI) and Fourier image (FI) planes for the fixed input linear polarization (LP) state |y > (θLP = 90°) and dynamic wave plate (DWP) orientation (θDWP = 45°) at λ = 800 nm, showing polarization modulation between orthogonal (a) LP states (|x >, |y >), corresponding to zero-wave plate (ZWP)/half-wave plate (HWP) transformation, by changing the actuation voltage Vm from 20.2 to 17.1 V, and (b) circular polarization (CP) states (|r >, |l >), corresponding to quarter-wave plate (QWP)/three-quarters-wave plate (TQWP) transformation, by changing the actuation voltage Vm from 19.1 to 14.4 V. For the FIs, the light is filtered using an iris letting through only light reflected from inside the orange dashed circles (shown in DIs). The leftmost column in (a, b) indicates the polarizer orientations used for filtering the respective polarization states in the reflected light. Scale bars in the DIs and FIs are 10 μm and 0.02k0, respectively. c, d Temporal evolution of the reflected light power for c ZWP/HWP and d QWP/TQWP transformations, measured by actuating the MEMS mirror with a periodic rectangular signal and filtering respective polarization states.
