Single-Mode Fiber Coupler, For Bare Fibers

The F-915 Single-Mode Fiber Coupler offers efficient single-mode coupling of a laser beam into a bare single-mode optical fiber. It provides the sub-micron positioning resolution necessary for high single-mode coupling efficiency. Fine translation is obtained in these couplers, without changing the angular orientation of the focused beam on the fiber end face. Unlike conventional couplers, in which positioner runouts can exceed fiber misalignment tolerances, the fine-tuning tilt adjustments introduce only a second order translation of the beam. Sub-micron resolution, required to optimize coupling to single-mode fibers, is provided by the kinematic tilt stage that uses fine, 100-pitch adjustment screws to pivot the lens/fiber-holder assembly. Focus and coarse transverse adjustments, required to position the focused laser beam on the fiber end face, are provided by the three-axis positioner that holds the fiber chuck. An M-Series microscope objective is also required. The couplers’ optical axis height is fixed at a nominal 3 inch (75 mm), and they have a pattern of tapped and clearance holes in their base for convenient mounting on Newport tables and breadboards.