High-resolution distance meter using optical intensity modulation at 28 GHz

A high-resolution distance meter was fabricated using optical waveguide modulators. An optical intensity modulation frequency of 28 GHz was utilized for the displacement measurement when the driving frequencies to the optical modulators were around 14 GHz. The distance meter was evaluated in the National Research Laboratory of Metrology (NRLM) tunnel, which is a semi-underground tunnel. The measurement resolution is 1 and for a distance of 5 and 100 m, respectively, in one standard deviation after correction of the cyclic error. Furthermore, cyclic errors are examined for 28 GHz optical intensity modulation.