Keywords: 
• 局部微结构长周期光纤光栅 /
• 温度 /
• 弯曲 /
• 双参量测量

Abstract: A local micro-structured long period fiber grating (LMSLPFG) is proposed and investigated experimentally. The LMSLPFG is fabricated by using hydrofluoric acid (HF) to partially etch a standard long-period fiber grating (LPFG), thereby forming a local defect in the cladding. The theoretical analysis and experimental results show that partially etching will change the effective refractive index modulation in the cladding mode, which equivalently introduces a phase shift into the part of defect and manifests, in the spectrogram, as openning a transmission window between the stopbands, forming two transmission stopbands and one transmission passband. On this basis we study the temperatures and bending characteristics of the two stopbands and one passband. The results show that the temperature sensitivities of the two stopbands and one passband are all approximately 0.05 nm/?C;the bending sensitivity of the passband (2.61 nm/m-1) is less than those of two stopbands (4.71 nm/m-1). Thus by using the sensitive matrix, we can simultaneously measure the curvature and temperature, with only one grating used.