Linearly chirped erbium-doped fiber laser

Linear tuning the frequency of an erbium-doped fiber laser over a 46-nm spectral range is demonstrated using a rotating mirror/grating combination as one of the reflectors in a Fabry-Perot laser cavity. The rate of frequency change is determined by monitoring the fringes produced when the laser light reflects from a fiber Fabry-Perot interferometer (FFPI). A root mean square variation of the tuning rate of <0.2% over the entire range is achieved using feedback from the FFPI to adjust the voltage ramp which drives the rotating mirror. The measured spectral width of the laser is 33 pm (4.2 GHz).