11 November 2010 Time-of-flight measurement with femtosecond pulses for high precision ranging lidar
Author Affiliations +
The time-of-flight of light pulses has long been used as a direct measure of distance, but the state-of-the-art measurement precision using conventional light pulses or microwaves reaches only several hundreds of micromeres. This is due to the bandwidth limit of the photodetectors available today, which is in the picosecond range at best. Here, we improve the time-of-flight precision to the nanometer regime by timing femtosecond pulses through phase-locking control of the pulse repetition rate using the optical cross-correlation technique that exploits a second-harmonic birefringence crystal and a balance photodetector. The enhanced capability is maintained at long range without periodic ambiguity, being well suited to terrestrial lidar applications such as geodetic surveying, range finders and absolute altimeters. This method could also be applied to future space missions of formation-flying satellites for synthetic aperture imaging and remote experiments related to the general relativity theory.
© (2010) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
J. Lee, J. Lee, Y.-J. Kim, Y.-J. Kim, K. Lee, K. Lee, S. Lee, S. Lee, S.-W. Kim, S.-W. Kim, } "Time-of-flight measurement with femtosecond pulses for high precision ranging lidar", Proc. SPIE 7860, Lidar Remote Sensing for Environmental Monitoring XI, 78600O (11 November 2010); doi: 10.1117/12.878899; https://doi.org/10.1117/12.878899

Back to Top