Reduction of cyclic error induced by electromagnetic contamination in an EO-comb based distance measurement system

In this work, we study the impact of cyclic error on the linearity of a distance measurement system based on an electro-optic (EO) comb and a heterodyne interferometer. The EO comb with 10 GHz repetition rate and 1.91 ps pulse duration is generated by modulating a 1540-nm CW laser through cascaded intensity and phase modulators. The cyclic error that induced by electromagnetic contamination from the driven signal of acoustic-optic frequency shifter (AOFS) are simulated and experimentally verified. The amplitude of the cyclic error corresponds well with numerical simulation. Through separating the optical part and electrical part, the cyclic error is effectively reduced.