HiBi-PCF-FLM (fiber loop mirrors made of highly birefringent photonic crystal fiber) stress sensor based on strength detection differential demodulation and device

Abstract

The invention relates to a HiBi-PCF-FLM (fiber loop mirrors made of highly birefringent photonic crystal fiber) stress sensor based on strength detection differential demodulation and a device. In the invention, two ports on one side of a 3dB coupler are respectively optically connected with a wideband light source and the incident end of a wavelength division multiplexer; two ports on the other side of the 3dB coupler are respectively optically connected with both ends of a HiBi-PCF (highly birefringent photonic crystal fiber); and the fifth channel and the sixteenth channel of the wavelength division multiplexer are two emergent ports which are optically connected with a photoelectric converter and a signal processing unit. The 3dB coupler and the HiBi-PCF form the sensing element of the HiBi-PCF-FLM; and the wavelength division multiplexer, the photoelectric converter and the signal processing unit constitute the demodulator of the optical fiber sensor. The HiBi-PCF-FLM stress sensor can eliminate the interferences caused by the light source jitter and various kinds of unstable factors of the sensing system, thereby greatly improving the system accuracy.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing, and relates to a high birefringent photonic crystal fiber loop mirror (fiber loop mirrors made of highly birefringent photonic crystal fiber, HiBi-PCF-FLM) stress sensor based on differential demodulation of intensity monitoring. Background technique [0002] High birefringence fiber loop mirror (fiber loop mirrors made of highly birefringent fiber, HiBi-FLM) sensor is a new type of fiber optic device developed in recent years. At present, HiBi-FLM has been applied in WDM filters and sensors due to its advantages of input polarization independence, high extinction ratio and low cost. However, when HiBi-FLM measures stress or other physical quantities, the cross-sensitivity to temperature limits the wide application of HiBi-FLM sensors. Photonic crystal fiber (PCF) is a new type of optical fiber with excellent optical properties. The cross-sensitivity of the sensor to temperature c...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the problem of low accuracy of the HiBi-PCF-FLM sensor demodulation unit in the prior art, and provide a HiBi-PCF-FLM temperature sensor based on intensity detection differential demodulation. This demodulation scheme can be effectively Eliminate interference caused by light source jitter and unstable factors in the sensing system

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