FULL DUPLEX LASER COMMUNICATION TERMINAL ARCHITECTURE WITH RECONFIGURABLE WAVELENGTHS

A full duplex dual red/blue wavelength communication architecture and method provides enhanced network configuration flexibility by enabling terminal switching between red and blue configurations, thereby enabling wavelength reconfiguration within the network on command while the terminal is in the field, airborne, or on orbit. A transmit laser module includes separate "red" and "blue" linear polarized lasers, or a single linear polarized laser tunable from red to blue. The transmit/receive diplexer uses a linear polarized beam splitter and a waveplate to transition the output beam between left and right circular polarization without affecting precision pointing, or co-boresight transmit/receive alignment. Waveplate polarization can be switched by physical rotation, or electrically using a liquid crystal variable retarder (LCVR). Red and blue bandpass filters can be selected in the receiver and/or transmitter by physical manipulation, optical switches, DWDM 3-port filters, and/or LCVRs. Two-laser embodiments can include a retroreflector for receiver optics self-calibration.