Optical Digital/Analog Converter

An optical digital-to-analog converter comprising:

• a first splitter configured to split a single light beam into N light beams corresponding to bits of an N-bit electrical digital signal and make the N light beams different in optical intensities such that (N−1) light beams corresponding to the bits except a least significant bit of the N-bit electrical digital signal each have an optical intensity which is a predetermined multiple of an optical intensity of a light beam of the N light beams corresponding to a next less significant bit of the N-bit electrical digital signal, wherein N is an integer of 2 or more;
• an optical intensity modulator configured to individually intensity-modulate the N light beams according to corresponding bits of the N-bit electrical digital signal;
• and
• a combiner configured to combine the N light beams into a combined light beam and output the combined light beam.

A method of operating an optical digital-to-analog converter, the method comprising:

• splitting, by a first splitter, a single light beam into N light beams corresponding to bits of an N-bit electrical digital signal and making the N light beams different in optical intensities such that (N−1) light beams corresponding to the bits except a least significant bit of the N-bit electrical digital signal each have an optical intensity which is a predetermined multiple of an optical intensity of a light beam of the N light beams corresponding to a next less significant bit of the N-bit electrical digital signal, wherein N is an integer of 2 or more;
• individually intensity-modulating the N light beams according to corresponding bits of the N-bit electrical digital signal by an optical intensity modulator;
• and
• combining, by a combiner, the N light beams into a combined light beam and outputting the combined light beam.