Characterization and cure monitoring of epoxy-cured fiber optic connectors via fiber optic sensors.

摘要

Optical Fiber Connectors are passive components used to link two fiber links or a fiber link to a photonic device. One widely used type of fiber connector, a design that uses a thermally cured epoxy adhesive, has been evaluated via strain sensors. Strain sensors were used to evaluate the strain incurred by the optical fiber as a result of installation and subsequent environmental testing. Discussed will be preliminary mechanical modeling, and a strain analysis using Bragg grating (BG) based strain sensors. Since the stain sensors were not exposed to uniaxial loading, mechanical modeling was used to determine the optimum placement of the sensors and the expected response. Also discussed are ongoing studies to evaluate the viscoelastic behavior of the epoxy and its effect on the strain state of the connector assembly.; Many fiber optic components utilize a thermally cured, epoxy resin as an adhesive. The properties of this solidified epoxy, determined typically by composition and cure schedule, are frequently evaluated experimentally by differential scanning calorimetry (DSC) and thermomechanical analysis (TMA). A disadvantage of these techniques is that they measure the properties of bulk samples. In practice, the epoxy is typically in a thin-film form. The properties of a thin film are not necessarily the properties of a bulk sample. A technique is presented that measures the glass transition temperature (T _g) in fibers encapsulated in zirconium ferrules by use of an in-situ strain sensor, a Bragg grating. This technique has the advantage that it can determine the T_g of the epoxy in the environment and geometry of use. Using this technique will allow a manufacturer or end user to qualify a product based on direct measurements of the product itself and not information supplied by a vendor or bulk sample measurements, which may not be accurate for a specific application. Since fibers adhered in ferrules are used in a variety of optoelectronic products, this technique has broad-ranging applications.