Asymmetric Textured Image Sensors Based on Antenna Theory as Designed by Nature

Abstract

This work numerically validates the application of bio-inspired concepts on CMOS derived from bacterial photosynthetic light harvesters. We investigate a modification of symmetric inverted pyramid array CMOS image sensors into an asymmetrically shaped texture to explore the structural boundary of passive non-reciprocity. Diverging from traditional macroscopic continuum assumptions, we analyze whether structural asymmetry at sub-wavelength scales can induce non-reciprocal scattering under passive, linear, and time-invariant conditions. A theoretical framework based on perturbation theory is developed, estimating a potential efficiency enhancement of 5\% to 15\%. Numerical simulations performed via the MEEP finite-difference time-domain (FDTD) platform reveal that the linear response is highly localized, showing a subtle 0.02\% change. This suggests that macroscopic Lorentz reciprocity remains robust at the investigated scale due to apex field concentration, defining a clear geometric threshold for microscopic non-reciprocity.