A low-finesse Fabry-Perot interferometer for use in displacement measurements with applications in absolute gravimetry

摘要

A low-finesse Fabry-Perot interferometer is used to determine long and fast displacements. Two corner cube reflectors form the traveling-wave cavity and one beam splitter couples the input collimated laser beam. Given the retro-directive property of corner cube reflectors, the cavity operates at the edge of stability over an extended scanning range. The in-line scheme with a single fixed optical component makes the proposed interferometer robust and easy to align and use. These characteristics are particularly useful in applications running in noisy environments, such as in on-field absolute gravimetry. Experimental data showing the performances reached in a transportable ballistic gravimeter are also presented.