Boosting Lyot Filter Sensitivity with Simulated Reference Sensor and Vernier Effect

In this work, we propose to use the Vernier effect to increase the temperature sensitivity of a Lyot filter using a simulated interference signal as a reference sensor. Unlike the traditional approach, which relies on two physical sensors, this method uses a single fiber sensor, providing a more adaptable sensitivity. The temperature sensitivity of the Lyot filter is -0.996 nm/°C; using this method, it is possible to accomplish magnifications of 15 and 20, which generate sensitivity of 14.5 and 19 nm/°C, respectively. This sensor can change the temperature sensitivity according to the necessities.

I. Introduction

The Vernier effect is a technique that can improve the sensitivity of a fiber optic sensor (monitoring sensor) using another sensor (reference sensor) with a similar free spectral range (FSR). Unfortunately, physical reference sensors are susceptible to external perturbations. To solve this issue, researchers proposed the Vernier effect based on a simulated interference pattern (SIP) [1], which fundamentally isolates the reference sensor. The SIP is generated via computer assistance and combined with the monitoring sensor signal to achieve the optical Vernier effect. The FSR of the reference sensor can be adjusted in situ for tunable sensitivity. The SIP has potential applications in high-sensitivity measurements and real-time monitoring fields.