(under subclass 189) Subject matter wherein a locally generated voltage at the received carrier frequency will result in a zero beat reception for detection of the
transmitted information signal.
(1) Note. This is also called a zero-beat demodulator.
(2) Note. Any further processing of the output of the demodulator will use electrical signals since the intermediate frequency (IF) output is outside the frequency spectrum of optical signals.
(3) Note. An electrical or optical local oscillator used in combination with a homodyne optical receiver is classified in this subclass.
