NONMECHANICAL MICROSCANNING USING OPTICAL SPACE-FED PHASED-ARRAYS

A method for microscanning in imaging sensors is developed that allows liquid-crystal beam steerers to be used as nonmechanical microscan de vices. This submicroscanning method involves using the beam steerers t o shift images on a focal-plane array by a fraction of the amount used in typical microscan methods. Interpolation techniques based on inter laced sampling are used to produce images free of aliasing out to twic e the Nyquist frequency determined by the focal-plane array. Since a c ontinuous phase ramp is produced by the liquid-crystal beam steerer, d ispersion effects due to the gratinglike nature of the devices are avo ided. Simulations for both one- and two-dimensional cases are presente d, as well as experimental results using a 3- to 5-mu m imaging sensor and a liquid-crystal beam steerer designed for operation at 1.064 mu m.