Share Email Print
cover

Proceedings Paper

Measurement of Brillouin gain spectrum distribution along an optical fiber by direct frequency modulation of a laser diode
Author(s): Takemi Hasegawa; Kazuo Hotate
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

A novel scheme for measuring Brillouin gain spectrum distribution along an optical fiber is developed. This scheme utilizes direct frequency modulation of a laser diode for two purposes: generation of the pump and probe lightwaves, and position-selective excitation of stimulated Brillouin scattering. A laser diode is modulated with a rectangular-wave signal, so that the pump and probe lightwaves for Brillouin gain spectrum measurement are generated in time-division manner. A sinusoidal-wave signal is mixed with the modulation signal for spreading the spectra of the pump and probe lightwaves. Because of the spread spectra, stimulated Brillouin scattering occurs in a small section of the fiber where the two lightwaves are highly correlated. The Brillouin gain spectrum at the section is obtained selectively. The section to be measured is chosen by varying the period of the sinusoidal modulation. Experimental result of measurement of the Brillouin spectrum distribution with a spatial resolution of 70 cm is presented. As a comparison, another system is demonstrated, where the probe lightwave is generated by intensity modulation with LN modulator. Spatial resolution of about 6.5 cm is achieved.

Paper Details

Date Published: 9 December 1999
PDF: 11 pages
Proc. SPIE 3860, Fiber Optic Sensor Technology and Applications, (9 December 1999); doi: 10.1117/12.372976
Show Author Affiliations
Takemi Hasegawa, Univ. of Tokyo (Japan)
Kazuo Hotate, Univ. of Tokyo (Japan)


Published in SPIE Proceedings Vol. 3860:
Fiber Optic Sensor Technology and Applications
Michael A. Marcus; Brian Culshaw, Editor(s)

© SPIE. Terms of Use
Back to Top