Optical arithmetic unit

An optical computing device, comprising:

• cascade-connected N elements, wherein N is an integer greater than or equal to two, and wherein each of the N elements comprises:
• a first optical input port and a second optical input port, wherein the first optical input port and the second optical input port receive one or two signal lights, wherein no light is input to the first optical input port or a signal light from a respective first output port of a previous stage of the N elements is input to the first optical input port;
• and
• a first output port;
• and
• N optical modulators, wherein each of the N optical modulators individually modulate a continuous light to a respective second optical input port of a respective element of the N elements in accordance with respective bits of an N-bit electric digital signal to generate a signal light for the respective second optical input port, wherein an output light acquired from a final element in a final stage of the N elements is at least part of a computing result,
• wherein each of the N elements is a coupling or branching element,
• wherein a first element of the N elements is a coupling element,
• wherein each of the N elements other than the first element further comprises a second output port,
• wherein the N elements are cascade-connected such that for each of the N elements other than a second element of the N elements, the respective first output port of the previous stage of the N elements is input to the first optical input port, wherein the previous stage of the N elements is an immediately previously stage of the N elements, and wherein the second element is a most upstream element of the N elements,
• wherein N optical modulators individually modulate N continuous lights having a same wavelength, and
• wherein a respective output light from a respective second output port of each of the N elements other than the first element and the output light acquired from the final element in the final stage of the N elements is the computing result.

An optical computing device, comprising:

• cascade-connected N elements, wherein N is an integer greater than or equal to two, and wherein each of the N elements comprises:
• a first optical input port and a second optical input port, wherein the first optical input port and the second optical input port receive one or two signal lights, wherein no light is input to the first optical input port or a signal light from a respective first output port of a previous stage of the N elements is input to the first optical input port;
• and
• a first output port;
• and
• N optical modulators, wherein each of the N optical modulators individually modulate a continuous light to a respective second optical input port of a respective element of the N elements in accordance with respective bits of an N-bit electric digital signal to generate a signal light for the respective second optical input port, wherein an output light acquired from a final element in a final stage of the N elements is at least part of a computing result,
• wherein each of the N elements is a coupling or branching element,
• wherein each of the N elements comprises a second output port,
• wherein the N elements are cascade-connected such that for each of the N elements other than a first element of the N elements, the respective first output port of the previous stage of the N elements is input to the first optical input port, wherein the previous stage of the N elements is an immediately previous stage of the N elements, and wherein the first element is a most upstream element of the N elements,
• wherein the N optical modulators individually modulate N continuous lights having a same wavelength,
• wherein the optical computing device further comprises:
• cascade-connected N−1 second elements, wherein each of the N−1 second elements comprises:
• a third optical input port, wherein the third optical input port receives a signal light from a respective second output port of a respective one of the N elements;
• a fourth optical input port, wherein a signal light from a respective third output port of an immediately previous stage of the N−1 second elements is input to the fourth optical input port;
• and
• a third output port,
• the output light acquired from the final element in the final stage of the N elements is a N-bit digital analog computing result, and
• an output light acquired from a final second element in a final stage of the N−1 second elements is a N-bit counter computing result.