title: Ultra-high-speed phase-sensitive optical coherence reflectometer with a stretched pulse supercontinuum source.
abstract: We demonstrate an ultra-high-speed phase-sensitive time-wavelength-domain optical coherence reflectometer with a stretched pulse supercontinuum source. A pulsed fiber laser operating at 10 MHz repetition rate was used to generate a pulsed supercontinuum of 30 ps pulse duration by using a nonlinear optical fiber. The supercontinuum pulses are stretched into 70 ns pulses with a highly dispersive fiber. With this stretched pulse source, we have built a phase-sensitive optical coherence reflectometer that measures the spectral interferogram of reflected light. By using the linear relation between the wavelength and the temporal position in a linearly chirped pulse, ultra-high-speed spectrum measurement can be obtained with this method in the time domain. We have demonstrated ultra-high-speed two-dimensional surface profiling for a standard image target and high-speed single-point monitoring for a fixed point under vibrational motion. It is shown that the measurement speed for the position of a single point can be as fast as 2.5 MHz, while the position accuracy can be better than 4.49 nm.
authors.affiliation: School of Information and Mechatronics, Gwangju Institute of Science and Technology, 261 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712, South Korea.
authors.forename: Hoseong
authors.initials: H
authors.lastname: Song
authors.forename: Seung Bum
authors.initials: SB
authors.lastname: Cho
authors.forename: Dong Uk
authors.initials: DU
authors.lastname: Kim
authors.forename: Sungho
authors.initials: S
authors.lastname: Jeong
authors.forename: Dug Young
authors.initials: DY
authors.lastname: Kim
mesh_terms: D004867:Equipment Design; D007834:Lasers; D055100:Optical Fibers; D055620:Optical Phenomena; D041623:Tomography, Optical Coherence / Q000295:instrumentation* / Q000706:statistics & numerical data