Efficient Faraday rotation in birefringent optical microfibre loop resonators for current sensing

Abstract

The optimization of resonantly enhanced Faraday rotation in microfiber loop resonators with linear birefringence is presented. For a sufficiently large birefringence-induced resonance separation, the evolution of differential phase between the two orthogonal polarizations can lead to efficient Faraday rotation when the loop circumference is a quarter of the polarization beat length and the roundtrip phase of the eigenmode in the fast axis is 3π/2 plus an integer multiple of 2π. This study provides the groundwork for fabricating microfiber loop resonator based current sensors that can operate efficiently despite the presence of birefringence.

Ultra-fast Hygrometer based on U-shaped Optical Microfiber with Nanoporous Polyelectrolyte Coating

“…The sensor head starts with the uniform-waist section of a biconical fiber taper, known as an optical microfiber. Optical microfibers are widely used for sensing 15 – 18 , due to their excellent optical (e.g. evanescent field of light, immunity against EMI) and mechanical qualities (e.g.…”

Optical Microfiber Technology for Current, Temperature, Acceleration, Acoustic, Humidity and Ultraviolet Light Sensing

“…In the work of Chen et al [ 41 ], geometrical optimization was studied for the simpler MLR to overcome the OPL limit. Unlike a typical MCR, a MLR shown in Figure 11 has negligible linear birefringence from its polarization-dependent coupling coefficients due to its much shorter coupling-length.…”

A Review of Microfiber and Nanofiber Based Optical Sensors

“…The wavelength shift was measured to be linearly proportional to the square of the current and a maximum tuning slope of 51.3 pm/A 2 was obtained. MLRs were theoretically investigated by Chen et al [212], and were found to exhibit optimum geometries that could host efficient Faraday rotation despite the presence of birefringence. A set of design rules were established for manufacturing non-ideal MLR sensor heads with a high sensitivity to current.…”