Patent ID: 7564387

Claim:
An optical analog-to-digital converter for converting an optical analog signal to an optical digital signal, comprising: a plurality of channels, with each channel receiving the optical analog signal and a sampling optical signal and generating therefrom a bit of the optical digital signal, and with the plurality of channels including a first channel providing a most significant bit (MSB), a last channel providing a least significant bit (LSB), and a plurality of intermediate channels providing bits of lessening significance between the MSB and the LSB, and with each channel being formed on a common semiconductor substrate and including: an optical waveguide interferometer having a pair of waveguide arms, with the sampling optical signal being split and directed into each waveguide arm, and with the optical analog signal being directed into only one waveguide arm to produce a phase delay of the sampling optical signal in that waveguide arm, and with the optical waveguide interferometer generating an optical output signal by combining the sampling optical signal from the pair of waveguide arms; and an optical thresholding element to receive the optical output signal from the optical waveguide interferometer and to generate therefrom one of the bits of the optical digital signal.