Progress in laboratory R & D for fundamental physics space missions - weak light phase-locking, fibre-linked heterodyne interferometry, fibre delay line and picometre real-time motion control

摘要: Since 1992, we have engaged in laboratory studies for astrodynamical missions to test relativistic gravity the solar system. The techniques developed are also relevant other fundamental space such as LISA and interferometer astrometry. Here report our progress weak light phase-locking, long fibre-linked heterodyne interferometry, fibre delay line picometre real-time motion control during last year. We demonstrated that two lasers with offset locking up 2.5 GHz, linewidth after travelling through a 26.27 km is less than 1 mHz. For achieved 4.3 nW 3.4 mW local oscillator. improved side-polishing technique polish more eight fibres simultaneously reached tunable sensitivity high 85 - 90 dB liquid-drop tests. Using these side-polished fibres, currently process of making directional couplers lines. laser metrology, use mid-point cyclic averaging reduce nonlinearity error, fitting method cancel drift, 1.5 pm linearity. Currently, modulation averaging, reach measuring precision 560 motion-control 700 pm.