A fiber laser for effective generation of tunable single- and dual-wavelength mode-locked optical pulses

A scheme to produce wavelength-tunable pulses with gigahertz bit rate is demonstrated by active mode locking of a fiber laser. Fiber gratings are used in the setup to play the simultaneous roles of wavelength selective mirrors, tunable optical filters, and output fiber couplers, Single- and dual-wavelength, picosecond pulses are generated with a flexibility of switching between the outputs by polarization adjustment. A strain tuning process is successfully developed and a total operating range of 13.62 nm towards both shorter and longer wavelengths is demonstrated. Our experimental observations are in good agreement with the calculated results. (C) 1998 American Institute of Physics.