Random-access digitally-tuned coherent optical receiver

Abstract From the Canadian patent

Abstract, A selectively tunable coherent optical receiver includes a tunable laser for producing a selectable local oscillator frequency for receiving any one of a group of received optical channel signals. The tunable laser is controlled by a feedback loop and a digital processor that stores values of laser bias current. The arrangement produces an exact local oscillator frequency for operating with any one of the group of selectable received channel signals which are spaced over a range of optical carrier frequencies. This receiver avoids frequency sticking and very long pull-in time and determines when there is a missing channel or missing channels.