Abstract

Stimulated Raman scattering (SRS) in optical fibers has been mainly used for broadband amplifiers, tunable fiber lasers or pulse compressors¹. All of theses applications dealt only with the downshifted Stokes frequency ω_s=ω_p−Ω_R where amplification of a weak signal copropagating with a pump occurs when the signal wavelength falls in the Raman gain bandwidth. In the present work, we launched a weak signal pulse at the anti-Stokes frequency ω_as=ω_p+Ω_R along with the pump (fig. 1-a). Experimental results performed in the visible domain show a strong attenuation of this anti-Stokes signal (fig. 1-b) with an efficiency of-20 dB (fig.2-a) and the simultaneous conversion to a Stokes pulse (fig. 1-b) amplified exponentially with respect to the anti-Stokes input with a maximum gain of 15 dB (fig.2-b). In the absence of the input anti-Stokes signal, no Stokes ouput is detected for the same pump power level as in fig. 1-b which is below the usual stimulated Raman threshold of the fiber¹.

© 1998 IEEE