Method of evaluating a polynomial function using an array of optical modules

A method for providing an optical analog intensity that is approximately proportional to the value of a polynomial function expressible in the form ##EQU12## wherein p(x) is a function of x,

• x is any variable,
• n is any positive integer,
• the coefficients, a.sub.i, are any constants, variables, or constants and variables;
• comprising:
• directing input light of intensity approximately proportional to the coefficient a.sub.n to the input end of an nth optical module comprising at the input end a modulator whose output light intensity is approximately proportional to a known function of an electrical potential difference across it and at the output end a beam combiner,
• applying across the modulator, while the light is passing through it, a potential difference approximately proportional to a function of x such that the intensity of the output light from the modulator is approximately proportional to a.sub.n x,
• directing the output light from the modulator, through the beam combiner, to the output end of the optical module,
• directing input light of intensity approximately proportional to the coefficient a.sub.n-1, via the beam combiner, to the output end of the optical module, to combine with the output light from the modulator so that the intensity of the output light from the nth optical module is approximately proportional to a.sub.n x+a.sub.n-1,
• directing the output light from the nth optical module to the input end of an (n-1)th optical module essentially similar to the nth,
• applying across the modulator in the (n-1)th optical module, while the light received from the nth module is passing through it, a potential difference approximately proportional to a function of x such that the intensity of the output light from the modulator is approximately proportional to (a.sub.n x+a.sub.n-1)x,
• directing the output light from the modulator, through the beam combiner, to the output end of the optical module,
• directing input light of intensity approximately proportional to the coefficient a.sub.n-2, via the beam combiner, to the output end of the optical module, to combine with the output light from the modulator so that the intensity of the output light from the (n-1)th optical module is approximately proportional to (a.sub.n x+a.sub.n-1)x+a.sub.n-2,
• and so on, in the same manner, and finally to the first optical module, so that the intensity of the polynomial function output light from the first optical module is approximately proportional to
• ((((a.sub.n x+a.sub.n-1)x+a.sub.n-2)x+ - - - +a.sub.2)x+a.sub.1)x+a.sub.o.