Patent ID: 7463832

Claim:
A method for monitoring and compensating for thermal drift of an optical device receiving signals from an optical transceiver, wherein the optical device has a plurality of adjacent passbands, the method comprising: generating a first pair of optical signals, each of a predetermined magnitude and being sufficiently narrow to both fit within a single one of said passbands that represents a reference passband, and transmitting said first pair of signals over an optical medium in said reference passband, from said optical transceiver to said optical device; using said optical device to receive said first pair of optical signals over said optical medium and to transmit a second pair of optical signals over a return optical medium back to said transceiver; using said transceiver to receive said second pair of optical signals from said optical device; comparing said first and second pairs of optical signals; and from said comparison, determining a needed operating temperature change of said transceiver to cause a bandwidth shift of said first pair of said optical signals that maintains said first pair of optical signals centered within said reference passband.