Dang Trang NGUYEN^*, Junji ABOU, and Akihiro MORIMOTO

Department of Photonics, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan

(Received February 29, 2012; Accepted June 5, 2012)

Ultrashort optical pulse generation using a fiber FM laser is presented and analyzed in detail. Fiber FM laser operation is realized using a fiber ring with an internal phase modulator and an erbium-doped fiber amplifier. To compress FM laser pulses, an external dispersive single-mode fiber is employed. Furthermore, by external intensity modulation, the pulse background is removed. The background ratio of the generated ultrashort pulse is calculated and compared with the experimental results. The experimental results show an output optical pulse width of 1.77 ps and a spectral bandwidth of 0.5 THz.

Key words: fiber FM laser, ultrashort pulse generation, phase modulator, intensity modulator, single-mode fiber, dispersion, contrast ratio, pulse compression

^*E-mail address: gr0119ei@ed.ritsumei.ac.jp