Abstract: A method for creating nonuniform grating strengths within fiber optic includes exposing photosensitive fiber optic material to an optical source for various periods of time through a mask. As the fiber optic material is exposed, the grating strength of the fiber changes. By linearly exposing the fiber optic material to different durations of optical energy, nonuniform grating strengths are created within the fiber, thereby creating a fiber optic section having asymmetric grating strengths.

Abstract: A distributed feedback fiber laser having designed asymmetric power output ports is disclosed. The present invention uses nonuniform grating strengths in a laser cavity of an erbium doped fiber optic material to create nonuniform reflection within the cavity. The stronger the grating strength in a particular section of the cavity, the more reflectivity that section has. This construction results in a fiber laser having two output ports with different output intensities. In a method for creating nonuniform grating strengths within the fiber optic material, photosensitive fiber optic material is exposed to an optical source through a mask. As the fiber optic material is exposed, the grating strength of the fiber is changed. By linearly exposing the fiber optic material to different durations of optical energy, nonuniform grating strengths are created within the fiber.

Abstract: The disclosure describes a switchable optical delay device which is small, inexpensive, lightweight, has high cross-talk isolation, and is capable of sub-microsecond switching times. The delay device uses low-reflection terminations, a single input, and a single output to minimize cross-talk. The device is preferably integrated onto a substrate in either a trombone-shaped configuration or a more compact nested configuration.

Abstract: A passively controlled multiple output fiber laser system in which the frequency relationships between all of the optical outputs remain constant over time includes a plurality of fiber lasers for generating respective output beams. The lasers are positioned in close proximity to each other so that they experience the same environmental conditions. Each laser includes at least one Bragg reflection grating that controls the frequency and bandwidth of the laser's output beam. The Bragg gratings are formed so that they respond equally to environmental changes. In a preferred embodiment, the fiber lasers are made from a plurality of substantially identical photosensitive fibers, and Bragg gratings are exposed simultaneously under identical exposure conditions in each of the fibers. A multiple output fiber laser system suitable for heterodyne LADAR systems is also provided.