Quantitative strain sensing in a multimode fiber using dual frequency speckle pattern tracking
Abstract
We report an amplitude-measuring multimode fiber sensor capable of making quantitative strain measurements and extracting the algebraic sign of the strain. The Rayleigh-based sensor probes the fiber with pulses of alternating optical frequency and records the backscattered speckle patterns on a high-speed camera. We show that measuring the change in the speckle pattern induced by a change in optical frequency provides a form of in situ calibration, enabling the sensor to recover the magnitude and algebraic sign of the strain. The sensor, which can be positioned anywhere along 2 km of fiber, has a linear strain response, a 10 kHz bandwidth, and a strain noise of 10.2 p ε / √ H z .
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 03, 2020
- Source ID
- 10.1364/ol.383569
Entities
People
- Brandon Redding
- Matthew J Murray
Organizations
- United States Naval Research Laboratory