Measurement and modeling of the angular dispersion in liquid crystal broadband beam steering devices

Liquid crystal beam steering devices behave like blazed diffraction gratings: the design wavelength can be nicely diffracted into a single order. Unfortunately, the grating nature of these devices causes strong angular dispersion of the transmitted light when the incident beam contains a broad spectrum of wavelengths. We characterized the behavior of a liquid crystal beam steerer for broadband illumination. We report experimental measurements of the impulse response of the beam steering device as a function of illumination wavelength. We also compare our results to a theoretical analysis utilizing the beam-propagation method (BPM). We find that even a simple model of the phase profile gives good agreement with the experimental measurements. (C) 1996 Society of Photo-Optical Instrumentation Engineers.