All Fiber-Based Optical Transmitters and Switching Technologies

摘要

A coupled-cavity mode-locked fiber laser using three Bragg grating in tandem hasbeen demonstrated. The matching of cavity lengths of the two coupled cavities is not critical and the difference in length can be as large as 2 mm still achieving mode-looking. The pulse width of these mode-locked lasers is, longer than the transform-limited value Er-doped fiber lasers are very unstable an usually exhibit self-pulsing behavior. Using a high-gain Er-doped fiber, the instability caused by resonant pump perturbation can be suppressed. One method to suppress the self-pulsing problem is to increase the emission to absorption ratio. Another method is to introduce Ytterbium ions (Yb) into Er-doped fiber. Samples of non-linear CdSSe-doped fibers have been fabricated for single mode operation in the wavelength region between 980nm-1550nm. Linear absorption coefficiently was found to be 0.14 dB/cm at 1550nm. The nonresonant non-linear refractive index was found to be 1.8x10(exp-17)m2/W, 400 times greater than silica fiber.