Lyot Filter With Femtosecond Laser-Induced High Birefringence Single-Mode Fiber for Torsion, Transverse Load and Temperature Sensing

Abstract

We propose and experimentally demonstrate an all-fiber Lyot filter with femtosecond laser-induced high birefringence single-mode fiber (SMF) for torsion, transverse load and temperature sensing. With the femtosecond-laser processing technique, the SMF with the birefringence of 2.81 × 10-4 is manufactured by directly writing a straight cladding stress track parallel with fiber core and employed to form an all-fiber Lyot filter for sensing application. The sensitivities of the all-fiber Lyot filter with respect to torsion, transverse load and temperature are found to be -4265.669 nm/(rad/mm), -321.004 nm/(N/mm), and 0.271 nm/°C, respectively. The experimental results are powerful proof of the excellent performance of the femtosecond laser-induced high birefringence SMF based all-fiber Lyot filter for sensing application, which not only adds significantly new and important results to the fields of optical sensing, but also develops the application fields of femtosecond-laser processing technique and all-fiber Lyot filter.

Keywords

• Optical fiber sensors
• ultrafast processes in fibers
• fiber birefringence
• filters
• polarization interference