Small-Spot Direct UV Written Fiber Bragg Gratings in Multicore Fiber

A new method for defining Bragg gratings in optical multicore fiber is presented. Small-Spot Direct UV Writing enable different cores of a multicore fiber to be individually addressed, enabling spectral multiplexing at co-located positions. We demonstrate for the time the inscription of a seven core fiber using Small-Spot Direct UV Writing, achieving low cross talk and evaluating the bend sensitivity of the fiber.