Displacement metrology directly linked to a time standard using an optical-frequency-comb generator.

Laser-frequency-based displacement metrology and a control system directly traceable to a time standard are developed. The setup is based on a Fabry-Perot (FP) cavity. Two resonant frequencies of the FP cavity are probed for displacement measurement. An optical-frequency-comb generator is utilized to improve the measurement resolution. A displacement resolution of approximately 1.3 nm was achieved, and displacement control using a phase-locked loop was demonstrated.