Polarization-Based Angle Sensitive Pixels for Light Field Image Sensors With High Spatio-Angular Resolution

Abstract

This paper presents a new angle sensitive pixel design for use in light field image sensors. This new pixel, referred to as the macro-pixel, is comprised of seven sub-pixels, and can determine the light angles in the range from −45°to +45°. The range of detectable angles is only limited by the presence of routing metals in the vicinity of the pixels. Each macro-pixel captures incident light angle through the aid of sub-wavelength metallic structures at its focal plane. Unlike previous designs that needed a large number of sub-pixels to determine a limited range of the incident angles, the presented design requires only half as many sub-pixels while offering a comparatively large angle detection range.Index Terms-Polarization pixels, angle detection, quadrature pixel cluster, light field image sensor, linear angle sensitive pixels, Talbot pixels.

A Novel Hybrid CMOS Pixel-Cluster for Local Light Angle, Polarization and Intensity Detection with Determination of Stokes Parameters

“…Other simulation parameters are given in Table I. The first simulated cluster was the PPC [10,15]. It works based on the principle of polarization by absorption.…”

“…9(b) is modeled to be proportional to the square of the cosine of the angle and the area of the photodiode. Moreover, a cosine factor multiplier pro-portional to the angle of incidence was added according to Lambert's cosine law [15].…”

“…12. This is a 3D view of the cluster with δ C variation of the light incidence in the photodiode [10,13,14,15], consisting of a block of metal on the top of the four photodiodes in such a way that the area which receives the incidence of light is proportional to the light incident angle. As detailed in [14], in this cluster, the direction of incident light is determined as follows:…”

“…4 the angle of incidence is referenced. The PPC presents high sensitivity to both light polarization and local incident angle [4,10,15]. It is shown to be far more sensitive to incident angle variation than the classical Talbot's pixel [10].…”

“…In order to determine the incident angle sign the (QPC), that produces a fairly weak but linear response proportional to angle variation, was employed in [4,10,15]. The QPC is much less sensitive to angle variation than the PPC, notwithstanding its output is not symmetric around zero.…”