Extended depth of field of a diffraction limited imaging system using a spatial light modulator based intensity compensated polarization coded aperture

Abstract

Reducing the aperture size is a conventional technique to obtain extended depth of field (DOF) of an imaging sytem, but it is obscured by depleting illumination. Polarization coded apertures (PCAs) can be employed to circumvent this critical artifact. We experimentally demonstrate intensity compensated polarization encrypted apertures, which are designed using the polarization modulation characteristics of LC-SLM. PCAs are not limited by the aperture size and hence far-field point spread function (PSF) can be more conveniently recorded using these PCAs. We experimentally show that DOF of a diffraction limited lens and axial intensity of binary Fresnel zone plate (BFZP) is enhanced using PCAs with nominal intensity loss.