Microfluidic assistant beat-frequency interferometer based on a single-hole-infiltrated dual-mode microstructured optical fiber.
A microfluidic assistant beat-frequency interferometer based on a single-hole-infiltrated dual-mode microstructured optical fiber (DM-MOF) is proposed and demonstrated. The interferometer is constructed by inserting a piece of fluid-filled DM-MOF into two sections of single-mode fiber with slight core-offset. The mode-mismatch induced interferences with high-frequency dips and low-frequency envelope are observed in the transmission spectrum. Theoretical and experimental investigations reveal that the beat-frequency spectrum works from the interferences between LP(01) core mode and the components of LP(11) core mode with close but different frequencies. The deliberately infiltrated liquid rod in the air hole located at the second ring near the core of the DM-MOF enhances the sensitivity of the envelope to temperature or axial force. However, it shows little impact on the high-frequency dips. The distinguishing sensitivities of -959.22 pm/°C (-70.59 pm/°C) and 24.26 nm/N (-3.14 nm/N) for the envelope (dips) are simultaneously achieved in experiment, allowing for dual parameter measurement in such a compact structure.
Mingming
M
Luo
Yan-Ge
YG
Liu
Zhi
Z
Wang
Tingting
T
Han
Junqi
J
Guo
Wei
W
Huang
D007368:Interferometry / Q000379:methods*; D044085:Microfluidics / Q000379:methods*; D055100:Optical Fibers; D013057:Spectrum Analysis; D013696:Temperature