Analog-Digital Mixed Laser Frequency Tracking-Lock for Space Based communication Arbitrary Doppler-Shift compensation

Abstract:
An arbitrary frequency difference locking method for local oscillator laser is realized by coarse thermal frequency tuning and fine frequency control achieved by external modulation based on in-phase and quadrature (IQ) orthogonal modulation. We experimentally demonstrate the frequency tacking-lock of the oscillator laser to the carrier of BPSK and QPSK modulated signal.