Abstract
An optical fiber Mach-Zehnder interferometer based on an inner air-cavity with an open micro-channel structure is presented. The device is fabricated by using femtosecond laser to inscribe a cavity structure in the optical fiber core, followed by discharging the cavity area with a fusion splicer to form an inner air-cavity in the fiber core, and finally create an open micro-channel with the help of hydrofluoric acid corrosion. The fiber in-line interferometric device is miniature, robust, and stable in operation and exhibits a high pressure sensitivity of ~3351 pm/MPa, with an extremely low temperature cross-sensitivity of 2.58 kPa/°C.
Funding Information
  • National Natural Science Foundation of China (61975192)