Weak light phase locking aided by frequency division phase meter for intersatellite laser interferometry

Weak light phase locking is an important part of intersatellite laser interference ranging. Phase-locked loop (PLL) used to track the heterodyne optical signal. Owing shot noise, frequency and other kinds there a difference between internal PLL local oscillator signal, while detection range only one period. If exceeds at certain time, may enter wrong operating point under feedback regulation, resulting in cycle clip, which leads subsequent reconstruction errors. In this paper, clip diagnosis method based on background gravitational waves proposed. Based original PLL, auxiliary divider with larger introduced, can provide basis for judging whether occurs PLL. digital low-light model established evaluate influence various noise. The theoretical spectral density error given according two main noise (laser particle noise). Considering limited large lead jump, making work point. A meter smaller division be solve problem. First, input sine signal converted into in-phase square wave N division. Then determined by comparing output reduced 1/N through time-to-degital converter (TDC) theory established. simulation results show that realize wide current framework has ability judge jump weak locking. It weak- task represented LISA.