We propose a high-refractive-index(RI)sensor based on a no-core fiber(NCF)with a waist-enlarged fusion-taper(WEFT)structure,achieving high measurement accuracy with the assistance of the gated recurrent unit(GRU)neura...We propose a high-refractive-index(RI)sensor based on a no-core fiber(NCF)with a waist-enlarged fusion-taper(WEFT)structure,achieving high measurement accuracy with the assistance of the gated recurrent unit(GRU)neural network.This sensor integrates the NCF in series with single-mode fibers,forming the WEFT structure through arc discharge using a fiber fusion splicer to construct a modal interferometer.In the experiment,the proposed sensor has been used for high RI(ranging from 1.4330 to 1.4505)measurement.Due to the high RI being close to that of the optical fiber,traditional spectral interference dip demodulation produces nonlinear responses,increasing the measurement error in sensing.The GRU neural network algorithm is employed to train and test the recorded spectral samples,and the experimental results indicate that the coefficient of determination for this neural network model reaches 99.93%,with a mean squared error of 2.24×10-8(RIU).This deep learning model can be widely applied to similar fiber sensing applications and demonstrates significant potential for intelligent sensing within optical networks.展开更多
We experimentally detect high-refractive-index media (n > 1.5) using a surface plasmon resonance (SPR) sensor with a diffraction grating. While SPR sensors are generally based on the attenuated total reflection met...We experimentally detect high-refractive-index media (n > 1.5) using a surface plasmon resonance (SPR) sensor with a diffraction grating. While SPR sensors are generally based on the attenuated total reflection method using metal films, here, we focus on a method using a diffraction grating, which can detect relatively higher refractive-index media and is suitable for device miniaturization. In this study, we used the rigorous coupled-wave analysis method to simulate the dependence of the reflectance on an incident angle for media with refractive index values up to 1.700. In the experiment, a medium (n = 1.660 - 1.700) was successfully detected using this grating. Under the conditions of the grating (period: 600 nm, Au thickness: 40 nm) using a red laser (λ: 635 nm), a sharp decline in the reflectance and a rise in the transmittance at certain angles were confirmed, demonstrating the extraordinary transmission enabled by SPR. Because excitation angles changed with changes in the refractive index, we concluded that this method can be applied to sensors that detect high-refractive-index media.展开更多
基金supported by the Aeronautical Science Foun-dation of China(Grant No.2023M026068001).
文摘We propose a high-refractive-index(RI)sensor based on a no-core fiber(NCF)with a waist-enlarged fusion-taper(WEFT)structure,achieving high measurement accuracy with the assistance of the gated recurrent unit(GRU)neural network.This sensor integrates the NCF in series with single-mode fibers,forming the WEFT structure through arc discharge using a fiber fusion splicer to construct a modal interferometer.In the experiment,the proposed sensor has been used for high RI(ranging from 1.4330 to 1.4505)measurement.Due to the high RI being close to that of the optical fiber,traditional spectral interference dip demodulation produces nonlinear responses,increasing the measurement error in sensing.The GRU neural network algorithm is employed to train and test the recorded spectral samples,and the experimental results indicate that the coefficient of determination for this neural network model reaches 99.93%,with a mean squared error of 2.24×10-8(RIU).This deep learning model can be widely applied to similar fiber sensing applications and demonstrates significant potential for intelligent sensing within optical networks.
文摘We experimentally detect high-refractive-index media (n > 1.5) using a surface plasmon resonance (SPR) sensor with a diffraction grating. While SPR sensors are generally based on the attenuated total reflection method using metal films, here, we focus on a method using a diffraction grating, which can detect relatively higher refractive-index media and is suitable for device miniaturization. In this study, we used the rigorous coupled-wave analysis method to simulate the dependence of the reflectance on an incident angle for media with refractive index values up to 1.700. In the experiment, a medium (n = 1.660 - 1.700) was successfully detected using this grating. Under the conditions of the grating (period: 600 nm, Au thickness: 40 nm) using a red laser (λ: 635 nm), a sharp decline in the reflectance and a rise in the transmittance at certain angles were confirmed, demonstrating the extraordinary transmission enabled by SPR. Because excitation angles changed with changes in the refractive index, we concluded that this method can be applied to sensors that detect high-refractive-index media.
