Highly Sensitive Sensors Based on Photonic Crystal Fiber Modal Interferometers

Figure 1

The top figures show the cross-sections of polarization maintaining PCF (top-left) or high birefringence PCF (top-right), taken from [6]. The bottom drawing is a diagram of the Sagnac interferometer. OSA stands for optical spectrum analyzer, SMF for single mode fiber, and PCF for photonic crystal fiber.