Space-variant incoherent optical processing using color
Incoherent optical processing techniques offer superior noise immunity, among other benefits, over coherent optical processing techniques. However, the complex amplitude linearity exhibited by coherent optical systems that provides a natural means for performing operations on complex functions, is lacking with incoherent optical systems. Bipolar values, as well as complex values, must be synthesized in incoherent optical systems. Bipolar values can be represented with unipolar quantities by adding biases to the bipolar values, exponentiating them, taking their logarithms, or separating the positive and negative parts into two components. Complex values can be represented with the polar, rectangular, and ternary basis forms of complex numbers. These representations are applied to add and multiply, and to evaluate the 1-D and 2-D superposition integrals with complex functions in additive, subtractive, and hybrid additive- subtractive incoherent optical processing systems. Data obtained from laboratory models of those systems demonstrate the additive and multiplicative properties of the systems. Electronic post-processing schemes are suggested to decode the unipolar outputs. Electronic post-processing schemes decode the unipolar outputs.