Open AccessOptical time-of-flight measurement based on data transmission in a ring oscillator
Author(s) -
R. Noé,
Benjamin Koch,
D. Sandel
Publication year - 2009
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.17.022925
Subject(s) - optics , repeatability , physics , signal (programming language) , transmission (telecommunications) , allan variance , oscillation (cell signaling) , computer science , telecommunications , standard deviation , mathematics , statistics , biology , genetics , programming language
We introduce a novel optical propagation delay measurement scheme for distance estimation. It is based on a ring oscillator in which the oscillation signal is replaced by the clock information contained in optical data. A clock-and-data recovery can recover the oscillation signal at the receive end. Correlation of the received pattern with the transmitted pattern and a measurement of the bit duration by a frequency counter allow to determine the distance. The scheme has been realized at 1550 nm wavelength, using an externally modulated laser, a commercial 155.52 Mb/s clock-and-data recovery and a field-programmable gate array. Short-term repeatability is <10 microm at an equivalent free-space distance of 72 m. Measurement interval is 0.1 s. At 3 km distance the relative repeatability is 8.10(-8). The readout can be corrected with measured temperature data.