3 May 2017 Field-programmable gate array-controlled sweep velocity-locked laser pulse generator
Author Affiliations +
Abstract
A field-programmable gate array (FPGA)-controlled sweep velocity-locked laser pulse generator (SV-LLPG) design based on an all-digital phase-locked loop (ADPLL) is proposed. A distributed feedback laser with modulated injection current was used as a swept-frequency laser source. An open-loop predistortion modulation waveform was calibrated using a feedback iteration method to initially improve frequency sweep linearity. An ADPLL control system was then implemented using an FPGA to lock the output of a Mach–Zehnder interferometer that was directly proportional to laser sweep velocity to an on-board system clock. Using this system, linearly chirped laser pulses with a sweep bandwidth of 111.16 GHz were demonstrated. Further testing evaluating the sensing utility of the system was conducted. In this test, the SV-LLPG served as the swept laser source of an optical frequency-domain reflectometry system used to interrogate a subterahertz range fiber structure (sub-THz-FS) array. A static strain test was then conducted and linear sensor results were observed.
© 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)
Zhen Chen, Gerald Hefferman, Tao Wei, "Field-programmable gate array-controlled sweep velocity-locked laser pulse generator," Optical Engineering 56(5), 054102 (3 May 2017). https://doi.org/10.1117/1.OE.56.5.054102 . Submission: Received: 10 February 2017; Accepted: 17 April 2017
Received: 10 February 2017; Accepted: 17 April 2017; Published: 3 May 2017
JOURNAL ARTICLE
5 PAGES


SHARE
Back to Top