Robotic Arm for Fiber Optic Coupling Manipulation in Vacuum

Project goal: To develop a system that allows autonomous fiber-optic cable exchanging within a vacuum environment,and to develop fiber-optic pass-through that allows the system to exchange signals through a vacuum wall. Accurate angular positioning of light-collection fibers relative to both source and sample had to be established so that light from the source reflecting off the sample was properly characterized. The team designed an autonomous data-collection system to measure spectral reflectance for recovery of a sample’s bidirectional reflectance distribution function, or BRDF. A fiber-caddying system was designed to allow the programmed arm to selectone of the system’s three data-collection fibers. The fiber was moved to precise locations to facilitate measurements of the sample’s reflection across the fiber’s effective spectral region. The used fiber was remounted and the next fiber selected for use. A custom CF flange (a type of industry-standard vacuum flange) containing fiber-connection points and epoxy-sealed windows was designed, and two ThorLabs CF flanges were purchased to maximize outgoing transmission without compromising the vacuum seal. Tests were performed on the designs for the autonomous BRDF vacuum-measurement system to ensure reliable fiber interchange and maximal spectral reflectance recovery.