Multiplexable high-temperature stable and low-loss intrinsic Fabry-Perot in-fiber sensors through nanograting engineering

Abstract

This paper presents a method of using femtosecond laser inscribed nanograting as low-loss– and high-temperature–stable in-fiber reflectors. By introducing a pair of nanograting inside the core of a single-mode optical fiber, an intrinsic Fabry-Perot interferometer can be created for high-temperature sensing applications. The morphology of the nanograting inscribed in fiber cores was engineered by tuning the fabrication conditions to achieve a high fringe visibility of 0.49 and low insertion loss of 0.002 dB per sensor. Using a white light interferometry demodulation algorithm, we demonstrate the temperature sensitivity, cross-talk, and spatial multiplexability of sensor arrays. Both the sensor performance and stability were studied from room temperature to 1000°C with cyclic heating and cooling. Our results demonstrate a femtosecond direct laser writing technique capable of producing highly multiplexable in-fiber intrinsic Fabry-Perot interferometer sensor devices with high fringe contrast, high sensitivity, and low-loss for application in harsh environmental conditions.

Identifications and classifications of human locomotion using Rayleigh-enhanced distributed fiber acoustic sensors with deep neural networks

“…The detail laser inscription method and laser processing parameter optimization can be found in ref. 24 . The insertion loss of each Rayleigh-enhanced point went up following an increase in pulse energy when inscribing severe nanodefects.…”

“…The insertion loss of each Rayleigh-enhanced point went up following an increase in pulse energy when inscribing severe nanodefects. The optimal laser processing condition can produce nano-reflectors in sensing fiber with insertion loss at 0.0012-dB/reflector 24 .…”

Multiplexable Fiber pH Sensors Enabled by Intrinsic Fabry-Peìrot Interferometer Array

“…The detail fabrication process can be found in Ref. [13]. Five pairs of Rayleigh scattering points were induced by the laser to form five IFPI sensors.…”

Review of Optical Fiber Sensor Network Technology Based on White Light Interferometry

“…One of the advantages of the optical fiber white light interferometer is that multiplexing can be realized very easily. At present, SDM, TDM, and FDM technologies have been widely used in the field of the white light interference sensing technology [14][15][16][17][18]. The optical fiber sensing technology based on white light interferometry is a representative branch in the cross application of the optical fiber sensing technology.…”

“…Secondly, because the coherence length of the sensor signal is short, it can eliminate the time-varying interference of system stray light [16]. Finally, multiple sensing signals can be coherently multiplexed into one signal without the complicated time division multiplexing or frequency division multiplexing technology [17,18].…”