Characterizing polarizers with direct electrical readouts
The polarization of light is recognized as a key physical quantity in describing light-matter interactions. Polarizers quantitatively characterize the combinations of different polarizations in light beams. In practice, the operations of polarizers require bulky and expensive terminal photodetectors, e.g., spectrophotometer, to measure the spectral responses associated with different polarizations. To get rid of the unfavorable reliance on conventional photodetectors, polarizers having a Cu-ZnO junction for efficient hot-electron extraction have been designed to give rise to direct electrical readouts. Detailed photoelectric studies reveal the designed device excites guided-mode resonances with which the device exhibits polarization-dependent energy depositions in absorbable Cu, leading to distinct electrical responses between transverse electric and transverse magnetic polarizations. In specific, the electrical extinction ratio increases from 2.7 to 4.4 when resonance wavelength increases from 767 nm to 869 nm. In this work, COMSOL Multiphysics is used for optical simulations of devices. By constructing a model of the Cu-ZnO structure, we calculated the absorption characteristics and extinction ratio of the device at the resonant wavelength under different polarized light incidence conditions.The simulation results are mutually consistent with theoretical analyses, providing a basis for device structure optimization and evaluation of polarization detection performance.
