Composite structure having an embedded sensing system

摘要

A composite structure having an embedded sensing system is provided, along with corresponding systems and methods for monitoring the health of a composite structure. The composite structure includes composite material and an optical fiber disposed within the composite material. The optical fiber includes a plurality of quantum dots for enhancing its non-linear optical properties. The quantum dots may be disposed in the core, in the cladding and/or on the surface of the optical fiber. The optical fiber is configured to support propagation of the signals and to be sensitive to a defect within the composite material. The quantum dots create a non-linear effect, such as a second order effect, in response to the defect in the composite material. Based upon the detection and analysis of the signals including the non-linear effect created by the quantum dots, a defect within the composite material may be detected.

主权项

1. A system for monitoring a composite structure, the system comprising:
an optical fiber extending between opposed first and second ends with at least a portion of the optical fiber within the composite structure, the optical fiber including a plurality of quantum dots; a signal source proximate the first end of the optical fiber and coupled to the optical fiber to provide optical signals to the optical fiber for propagation therealong, wherein the signal source is configured to provide optical signals having first and second distinct input frequencies v1 and v2 with at least one of v1+v2or v1−v2 being resonant with a material excitation of the optical fiber; a reflector positioned in optical communication with the optical fiber so as to reflect the optical signals through the optical fiber toward the first end; and a detector coupled to the optical fiber to detect optical signals that exit the optical fiber from the first end of the optical fiber following reflection of the signals therethrough, wherein the plurality of quantum dots create non-linear properties including at least one of a second order harmonic or a third order harmonic in response to an anomaly in the composite structure that is detectable upon analysis of the optical signals that exit the optical fiber.