A high sensitivity gas pressure sensor based on femtosecond laser micro/nano processing

Abstract

A compact and novel Mach-Zehnder interferometer used for gas pressure sensing is proposed and demonstrated experimentally. The sensor is constructed by fusion splicing a short piece of dual side-hole fiber (DSHF) in between two sections of multimode fibers (MMF). Interference occurs as the optical path length difference (OPLD) between light beams along air holes and silica of the DSHF. With the opening drilled on one air hole by femtosecond laser micro/nano processing, the filled gas directly affects light beam along this air hole, which results in the interference spectrum shift. Experimental results show that the sensor exhibits a high sensitivity of −8.58 nm/MPa with the increasing gas pressure. The sensor has potential application in gas pressure sensing for its advantages of high sensitivity, low temperature crosstalk and easy fabrication.

Keywords:

• Mach-Zehnder interferometer
• side-hole fiber
• femtosecond laser
• gas pressure

Additional information

Funding

This work is financially supported by the Project of National Science Foundation of China, NSFC (No.61475121) and National Key Research and Development Program of China (No.2017YFC0804403).