Mach-Zehnder interferometer on cavity suspension channel type optical fiber cable

The utility model provides a Mach-Zehnder interferometer on a cavity suspension channel type optical fiber cable. The Mach-Zehnder interferometer comprises a broadband light source, a sensing head anda spectrum analyzer. Wherein the sensing head is formed by inscribing micro-rings on the end faces of single-mode optical fibers at the two ends through femtosecond laser and enabling the micro-ringsto be fused and butted. The method is characterized in that a femtosecond laser inscribes a micro-ring structure, high temperature generated by welding discharge enables air in the ring structure toexpand, and then a fiber core is extruded to form a suspension channel in a cavity. Due to the fact that the size of the channel is extremely small and is about 3 micrometers, part of light is transmitted along the channel, part of light is transmitted from the air cavity, and finally the two beams of light are coupled back to the single-mode fiber core. Light of the broadband light source is transmitted to the spectrum ana