Transform-Limited, Injection Seeded, Q-Switched, Ring Cavity Fiber Laser

We report an Er-doped, actively Q-switched, fiber laser, generating transform-limited pulses based on single-frequency fiber laser seeded ring cavity. The output pulsewidth can be tuned from hundreds of nanoseconds to several microseconds by changing the repetition rate or the open time of the electrical pulse trigger. This injection-seeded, Q-switched ring cavity fiber laser can be operated over the whole C-band. In addition, a theoretical model is developed to numerically study the pulse characteristics by changing the acousto-optic modulator transmission as well as several cavity parameters, such as the cavity length and loss. The numerical results are in good agreement with the experimental results.