Simultaneous Measurement Based on Composite Interference Structure

A novel double-parameters sensor based on composite interference structure has been designed and implemented in this letter. It can be regarded as a cascade of the traditional single mode-multimode-single mode structure and multimode-single mode-multimode structure. The output signal is a series of interference superposition; external parameters can be measured by monitoring the spectral characteristics of interference dips. The interesting properties of the sensor include good operation linearity. In addition, simultaneous measurement of temperature and refractive index have been achieved. The sensitivities of temperature and refractive index can reach up to 0.1385 nm/°C and 100.97 nm/RIU, respectively.