| Optical computing has proven useful in several specialized applications. General development of optical computing is limited by the computational inaccuracies typically found in optical information processing. One source of these inaccuracies is the noise generation and transformation properties of optical devices. The existing signal and noise models of these devices are inadequate for information processing system development. This is specifically true for spatial light modulators. Progress in optical computing requires more accurate models of these optical devices and their noise characteristics.;System modeling of optical devices is complicated by the multiple-port and nonlinear nature of those devices. The Volterra series model adequately represents a multiple-port, mildly nonlinear device and may be applied to continuous-time and discrete-time systems. Furthermore, these model characteristics may be measured experimentally. We present a multiple-input, single-output, weakly nonlinear model of spatial light modulators using a second-order Volterra series and describe an experimental method to measure the nonlinear transfer functions using sinusoidal perturbation and synchronous detection with a lock-in amplifier. Noise characteristics of optical devices are calculated directly from this system model using the nonlinear transfer functions. |
