Distributed Brillouin Fiber Laser Sensor: Karle Fellowship Final Report
Abstract
Distributed fiber sensors are a powerful tool for structural health monitoring and environmental sensing due to their ability to remotely monitor the strain at 1000s of locations using low-cost optical fiber. Sensors based on Brillouin scattering are uniquely suited to these task since they can make completely distributed, absolute measurements of strain, with a long range (>100 km), small sensing size (<1 cm), and a huge absolute dynamic range, all in standard off-the-shelf telecom fiber. These sensors function by measuring the resonance frequency of the non-linear Brillouin interaction in fiber which shifts linearly with strain and temperature. However, existing Brillouin sensors are hampered by fundamentally poor response resulting in small frequency shifts compared to the linewidth of the interaction. To overcome this limitation we introduced a technique known as distributed Brillouin fiber laser sensing (DBFLS) which establishes a series of narrowband lasing modes that experience Brillouin gain at discrete locations. The high intensity and narrow linewidth associated with the lasing transition enables high precision strain and temperature measurements. This work was conducted under my Naval Research Laboratory Karle Fellowship. This memo reviews the operation of the DBFLS and its performance and serves as a final report for the fellowship.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 25, 2022
- Accession Number
- AD1181123
Entities
People
- Joseph B Murray
Organizations
- United States Naval Research Laboratory