Two-mode photonic crystal fiber interferometer for temperature and strain sensing

A compact in-line interferometer is demonstrated by splicing a piece of two-mode photonic crystal fiber (TPCF) between two segments of single mode fiber (SMF). The TPCF is completely homemade and carefully simulated by finite element method based on the real cross section. It is firstly verified that the interference occurred between LP01 and LP11 even modes and the period of the interference pattern was inversely proportional to the length of TPCF. The temperatures and strain induced.