Optical fiber tap with ground core

A description of graded-index fiber tap is given. The tap is manufactured by grinding and polishing the fibers along the axis through the cladding into the core region. Measurements of the total loss and the mode dependent coupling using a near field analysis are described. Furthermore the light pulse propagation in a simulated series connection of the fiber taps is discussed. A tap with two unequally ground fibers shows low loss and equal excitation of all modes in the coupled fiber.