Rapid and scalable scans at 21 m/s in optical low-coherence reflectometry

An optical low-coherence reflectometer is presented that uses a fiber Michelson interferometer with a rotating cube to generate rapid depth scans at a high repetition rate. A folded optical path geometry allows the reference arm to scale up the scan range, scan speed, and scan repetitiveness. Thickness measurements with a repetitiveness of 384 Hz and a longitudinal scanning speed of 21 m/s in air over a range of similar to 3 mm are demonstrated. (C) 1997 Optical Society of America.