Absolute distance measurement using comb-spectrum interferometry

A measurement technique is proposed based on dispersive interferometry using a comb-spectrum source: dispersive comb-spectrum interferometry (DCSI). The configuration proposed processes the Michelson interferometer output by a dispersive grating in the Littrow configuration. Using a commercial low-cost laser diode source, the non-ambiguity measuring range was measured to be 1.6 mm, whereas the maximum permissible working distance, including ambiguity was measured to be 1.2 cm. The linearity error and stability were measured to be 1.2 mu m and 32 nm, respectively.