A compact, large-range interferometer for precision measurement and inertial sensing

We present a compact, fibre-coupled interferometer with high sensitivity and a large working range. We propose to use this interferometer as a readout mechanism for future inertial sensors, removing a major limiting noise source, and in precision positioning systems. The interferometer's peak sensitivity is $2\times {10}^{-14}$ m $\sqrt{{Hz}^{-1}}$ at 70 Hz and $7\times {10}^{-11}$ m $\sqrt{{Hz}^{-1}}$ at 10 mHz. If deployed on a GS-13 geophone, the resulting inertial sensing output will be limited by the suspension thermal noise of the reference mass from 10 mHz to 2 Hz. (paper)