Temperature Sensor Based on Er-Doped Cascaded-Peanut Taper Structure In-Line Interferometer in Fiber Ring Laser

A temperature sensor based on erbium-doped fiber cascaded peanut taper (EDFCPT) structure in fiber ring laser (FRL) cavity is proposed and studied. The cascaded peanut structure was fabricated by erbium-doped fiber. The cladding mode and core mode interference and the strong thermo-optical effect of erbium-doped fiber were used to realize the high sensitivity measurement of temperature. The mode interference and thermal sensitivity effects of EDFCPT in a broadband super-continuous light source and a fiber ring laser cavity were studied and compared experimentally. Besides, Erbium-doped fiber cascaded peanut (EDFCP) structure was designed to compare performance with EDFCPT. The experimental results show that EDFCPT has a higher signal to noise ratio (SNR) (similar to 50dB) and a narrower 3-dB bandwidth (similar to 0.12nm) than the broadband light source. Among them, the temperature sensitivity of EDFCPT is 571pm/degrees C which is two times higher than the EDFCP (similar to 249nm/degrees C) structure at range from 5 degrees C-55 degrees C. The proposed temperature sensor has the advantages of high sensitivity, good repeatability, simple fabrication, compact structure, etc. It has a good application prospect in the field of aerospace and life health monitoring.

Automated summary

A temperature sensor based on EDFCPT structure in fiber ring laser cavity was proposed and studied, utilizing erbium-doped fiber to fabricate the cascaded peanut structure for high sensitivity temperature measurement. Experimental results show that EDFCPT has higher temperature sensitivity, signal to noise ratio, and narrower bandwidth compared to EDFCP structure, indicating promising application prospects in aerospace and life health monitoring.