Programmable diffractive optics for wide-dynamic-range wavefront control using liquid-crystal spatial light modulators

Wide-dynamic-range wavefront control is demonstrated with a programmable 2-D high-resolution liquid-crystal-based phase modulator system. This system operates with 307,200 independently addressable phase modulating elements, a phase modulation range that exceeds 2, and phase resolution that is better than one-tenth of an optical wavelength at 532-nm wavelength. A demonstration of large aberration compensation via modulo-2 phase profiles shows high-fidelity wavefront compensation with less than one-quarter-wave peak-to-peak residual aberration. The results of a numerical model of diffraction efficiency via discrete phase-step approximations to modulo-2 tilt functions are presented. The model treats the effects of a variable fill factor and an interpixel influence function associated with this technology. Optimization of the diffraction efficiency includes computational compensation for nonlinearities in the system phase response. Measured diffraction efficiencies are compared to calculated values, and show operation near the theoretical limit for this system.