Systems and methods for reducing off-axis optical aberrations in wavelength dispersed devices

Abstract

Through its higher refractive index, a silicon grism can be used to reduce the Described herein are systems and methods for reducing optical aberrations in an optical system to decrease polarization dependent loss. Embodiments are provided particularly to define beam trajectories through an optical switching system which reduce off-axis aberrations. In one embodiment, a silicon grism is provided for reducing the curvature of the focal plane at an LCOS device in a wavelength selective switch (WSS) such that the separated polarization states converge at the LCOS at substantially the same point along the optical axis for all wavelengths. In this embodiment, an axial offset at the LCOS device will not produce large PDL at the coupling fibers. In another embodiment, a coupling lens having an arcuate focusing region is provided to address an offset in the optical beams, such that the separated polarization states couple symmetrically to respective output fibers.