| Weak light optical phase-locking is one of the key technologies for spacebornegravitational wave detection and the advanced Earth’s gravity recovery missions. Sincethe Earth’s gravity recovery is important for security of national defense, resourceexploration, geophysical research, it is planned to lunch satellite mission in the near futurein China, called SAGM （Space Advanced Gravity Measurement）. Therefore it’s verymeaningful at this moment to develop key technologies for advanced Earth’s gravityrecovery missions.In this thesis, we present the research and development of weak-light optical phaselocking that is aiming at achieving the requirement of inter-satellite laser ranging with adistance between two satellites of about200km. We started to study the homodyne opticalphase locked loop. The preliminary result showed that for a10-nW received light, thepower spectrum density of the residual phase error could achieve about4×10-4rad/Hz@0.1Hz, which is better than the target precision of6×10-3rad/Hz@0.1Hzfor advanced Earth’s gravity recovery mission. According tothe error analysis, the theoretical value of the noise level should be6×10-6rad/Hz,which is much less than that we obtained from experimental result. Besides, we integratedthis optical phase-locked system with a heterodyne laser interferometer to build up atransponder-type laser ranging system. For the laser beams with a power of1mW, theresidual phase error was2×10-4rad/Hz@0.1Hz, corresponding to a displacement（inter-satellite range） measurement of34pm/Hz@0.1Hz（λ=1064nm）. |
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