Conformal, Random Access Beam Steering for Broadband Systems

A large aperture achromatic holographic Risley prism equivalent system is proposed which provides conformal and fast scanning using ultra-light weight piezoelectric motors to achieve a large scan angle.The system is very efficient, simple and easily replicated.The central null issue normally associated with Risley prisms is eliminated with a 3rd weak achromatic displacement grating between the outer achromatic prism equivalent gratings.Beam characteristics are well preserved and it can handle high optical power.Diffraction efficiency is = 93% for a single holographic phase grating.Chromatic aberration is eliminated using a compensating hologram so the scanner operates over a broad spectral range.Zoom capability and optical power can be incorporated into the system to further extend its versatility eliminating external optics and reducing the size, weight and power requirements.