High-sensitivity low-cost temperature sensor based on symmetrical metal-cladding optical waveguide

Abstract

The temperature-dependent reflection spectrums of ultrahigh order guided modes of symmetrical metal-cladding waveguide (SMCW) are measured in angular interrogation. The results show that the reflection spectrum is characterized by extremely narrow resonance dip, which agrees well with numerical calculation. Based on the falling or rising edge of resonance dip of ultrahigh order guided modes of SMCW, a temperature sensor with characteristic of high sensitivity is proposed. Meanwhile, by experimentally determine the linear character between the shift of resonance angle and the variation of temperature, a method of angle compensation is put forward to extend the sensing range. Owing to its characteristics of high sensitivity, low cost and easy fabrication, the temperature sensor based on SMCW will be a promising sensor in many fields.