Dynamic measurements at up to 130-kHz sampling rates using Ti:sapphire dual-comb distance metrology

Abstract

By using fully-locked Ti:sapphire combs operating with repetition-frequencies of 513 MHz, we demonstrate high-speed dual-comb distance metrology with update rates up to 130 kHz, equivalent to a sampling interval of 7.7 µs. This measurement bandwidth is achieved by limiting detection to a wavelength range much less than the pulse bandwidth, enabling interferometric precision to be reached in a time of 2.6 ms and yielding a precision of 2 nm in 100 ms. The repetition frequency achieves an instantaneous non-ambiguity range of 29.2 cm, while the high sampling rate provides the ability to make dynamic measurements, which is demonstrated by using the system to directly sample audio waveforms by recording the displacement of a mirror mounted on a loudspeaker.