Widely tunable single-frequency Er-doped fiber laser with linear cavity

Summary form only given. Tunable single-frequency lasers operating in the wavelength region of 1.55 /spl mu/m have received great attention for applications such as wavelength-division-multiplexed (WDM) communication systems, spectroscopy, and fiber sensors. Compared to tunable semiconductor lasers that are commercially available in various forms, tunable single-frequency fiber lasers have potential advantages of narrow linewidth, low intensity noise, scalability to high output power, and fiber compatibility. A very short cavity fiber laser with fiber Bragg grating mirrors was tuned by applying a mechanical compressive force. A unidirectional ring laser with a tandem Fabry-Perot filter for mode selection could be tuned by tuning synchronously the two Fabry-Perot filters. We propose and demonstrate a simple widely tunable single frequency fiber laser, having a long linear cavity with all-fiber frequency shifters, an absorption grating, and electronic tuning mechanism.