[OPTICAL REVIEW Vol. 6, No. 1 (1999) 37-41]

Multi-sideband Generation in a Femtosecond Cr4+:YAG Laser

Yuzo ISHIDA,1,* Kazunori NAGANUMA1 and Hidehiko KAMADA2

1NTT Opto-electronics Laboratories, 3-1 Morinosato, Atsugi, 243-0198 Japan, 2NTT Basic Research Laboratories, 3-1, Morinosato, Atsugi, 243-0198 Japan

(Received June 19, 1998; Accepted November 4, 1998)

We describe the behavior of multi-sidebands in a self-mode-locked femtosecond Cr4+:YAG laser operating near 1.54 μm. Stokes and anti-Stokes sideband components are extended over 20 THz around the center frequency. An interesting feature here is that when the spectral width of the mode-locked pulse is increased, the specific Stokes sideband near 1.65 μm (a shift of 13.5 THz) is strongly enhanced due to an induced-Raman process in the laser rod. The measured frequency shifts for all sidebands are well explained by four-wave-mixing processes in the laser rod, accompanied by the resonance effect of the soliton and dispersive wave, both of which are affected mainly by cavity dispersions.

Key words : multi-sideband, Raman, four-wave-mixing, femtosecond, solid-state laser