-78-dB shot-noise limited optical low-coherence reflectometry at 42-m/s scan speed

We report, to our knowledge, the fastest longitudinal scans in optical low-coherence reflectometry published in literature. The use of a rotating glass cube as an optical path length variator results in a longitudinal scan speed of 42 m/s at a longitudinal scan repetition rate of 1240 Hz. The high-speed reflectometer is operated at the shot-noise limit corresponding to a sensitivity of -78 dB. The scalability of the scanning method with respect to scan speed, scan repetitiveness and scan length is demonstrated by the use of differently sized glass cubes.