Image-Based Phase Detection of Guided-Mode Resonance Sensors Using Pohl Interferometer

This paper uses a compact single-arm Pohl interferometer to perform an image-based phase detection system for a guided-mode resonance (GMR) sensor. The interference fringe shift of the Pohl interferometer is sensitive to the refractive index (RI) of the liquid flowing through the GMR sensor surface, and a low-cost image sensor was used to capture the image and measure the fringe shift in the proposed experiment system. The measurement results showed that the system could achieve an average detection sensitivity of 1703°/RIU.