The scanning-free, precise reconstruction of the local value of the Brillouin frequency shift in a section of optical fiber is proposed and demonstrated experimentally. The Brillouin shift is identified based on transient analysis of the step response of the amplified signal wave. The measurement protocol requires a single trace, taken at an arbitrary frequency offset between the central optical frequencies of the pump and signal waves. The frequency offset may be chosen anywhere within ±100 MHz of the Brillouin frequency shift, corresponding to a measurement range of ±100 °C or ±2,000 μepsilon. The experimental error between the estimated Brillouin shift and its true value is less than±1 MHz. The protocol is suitable to high-resolution Brillouin optical correlation domain analysis.

Date Published: 30 May 2016
PDF: 4 pages
Proc. SPIE 9916, Sixth European Workshop on Optical Fibre Sensors, 99162K (30 May 2016); doi: 10.1117/12.2236802

Published in SPIE Proceedings Vol. 9916:
Sixth European Workshop on Optical Fibre Sensors
Elfed Lewis, Editor(s)