High-sensitivity chirped tapered fiber-Bragg-grating-based Fabry–Perot cavity for strain measurements

Abstract

In this Letter, a novel, to the best of our knowledge, Fabry–Perot cavity, based on Bragg grating technology for temperature and strain monitoring, is presented. Such a structure consists of two linearly chirped fiber Bragg gratings of a significant length written in a thermally tapered optical fiber. The technological process for manufacturing such a grating allows for utilization of almost every tapered fiber, by means of its profile and also phase masks with various chirp ratios. For this type of structure, a method for strain discrimination based on monitoring of the cavity length is proposed, enabling potential multiplexation of the sensor of two structures, which have the similar reflection spectra, by means of their spectral position. The utilized sensing mechanism allowed for achieving strain sensitivity by means of the cavity length change as high as 5 µm/µɛ. Also, as it has been experimentally shown a structure can also be employed for measurements of temperature, with the sensitivity equal to 8.96 pm/°C.

Hot Spot Detection of Photovoltaic Module Based on Distributed Fiber Bragg Grating Sensor

“…Therefore, the change in the grating Bragg wavelength is related to its axial strain and temperature. When the temperature is measured by FBG, the interference of axial strain and temperature on the grating must be considered [30].…”

A Fiber Bragg Grating Borehole Deformation Sensor for Stress Measurement in Coal Mine Rock

“…FBG sensors are becoming more and more popular for geotechnical applications, and they are used to measure the strain [15,16], stress [17][18][19], displacement [20,21], and deformation [22][23][24] of the geotechnical media. In recent years, some unconventional FBG sensors, such as chirped FBG sensors [25] and tilted FBG sensors [26], are also proposed, and they show some advantages over traditional FBG sensors in some aspects.…”