Nonmechanical steering of the field of view of broad spectral band optical systems

Abstract

Methods of nonmechanically steering broad spectral band light will enable many low cost electro-optical systems that employ broadband sensors (such as flir or TV). Nonmechanical optical phased array approaches have been demonstrated for narrow band electro-optical systems. However these approaches tend to be highly dispersive because of the diffractive effects associated with the modulo 2p phase resets within the apertures. In this paper we describe approaches to compensate or minimize these dispersive effects. A means to compensate for the dispersion using wavelength independent phase modulators and achromatic Fourier transform lenses is discussed. A means to minimize dispersive effects through the use of larger-than-2p phase resets is also presented, including a possible means of implementing such an approach using cascaded microlens arrays that are electronically controllable. The addition of nonmechanical approaches for steering broadband radiation will significantly accelerate the revolution in electro- optical systems from conventional steering to non-mechanical steering.