Optical Fiber-Based Environmental Detection System and the Method Thereof

摘要

An optical fiber environmental detection system comprising an interferometer, a broadband light source and a detector is disclosed. The interferometer further comprises a thin core fiber, a first single mode fiber and a second single mode fiber; wherein the thin core fiber is coupled to the first and second single mode fiber via a first junction and a second junction respectively. When an emission light reaches the first junction, high-order cladding modes will be excited. The excited cladding modes will interfere with the core mode at the second junction. The interferences determine the intensity maximum or minimum of the received signal. When there is an ambient environmental change, a shift of the received signal would be induced. According to the shift, environmental change, for instance ambient temperature, could be determined.

主权项

1. An environmental detection system comprising:
a) an interferometer comprising a thin core fiber, a first single mode fiber and a second single mode fiber; wherein said thin core fiber has a core diameter thinner than said first single mode fiber and said second mode fiber and is coupled to said first single mode fiber via a first junction and to said second single mode fiber via a second junction; b) a broadband light source configured to emit an emission light and coupled to said first single mode fiber of said interferometer; thereby allowing said emission light to propagate from said first single mode fiber to said second single mode fiber through said thin core fiber; and c) a detector coupled to said second single mode fiber of said interferometer and configured to capture a signal from said interferometer; wherein said first junction creates a plurality of optical paths for said emission light and said second junction collects said plurality of optical paths to said second single mode fiber such that an environmental change altering said optical paths, and inducing a shift of said signal is detected by said environmental detection system.