Amplification effect on stimulated Brillouin scattering in the forward-pumped S-band discrete DCF fibers Raman amplifier

Abstract

The amplification effect on forward and backward stimulated Brillouin scattering lines in the forward pumped S band discrete DCF fiber Raman amplifier (FRA) has been studied. The pumped threshold power of the forward first order Stokes SBS (FSB 1 - ), second order Stokes SBS (FSB 2 - ) and third order SBS (FSB 3 - ) in the forward pumped FRA are 1.5 mW, 1.4 mW and 1.7 mW respectively. The Stokes SBS lines are amplified by FRA and fiber Brillouin amplifier (FBA) at the same time. The gain of amplification is given as G A =G R multiplied by G B where G R is Raman gain and G B is Brillouin gain. In the experiments, the saturation gain of FSB 1 - , FSB 2 - and FSB 3 - are about 52dB, 65dB and 65dB respectively. The saturation Raman gain of 10km DCF forward FRA is about 14dB, so the Brillouin gain of FSB 1 - , FSB 2 - and FSB 3 - are about 38dB, 51dB and 51dBrespectively. There are pumped threshold power of the first order, second order and third order Stokes backward SBS (B-SBS) line BSB 1 - , BSB 2 - and BSB 3 - in the forward pumped discrete DCF FRA, and they are about 4.7mW, 17.1mW and 67mW respectively. The saturation gain of the first order, second and third Stokes backward SBS line BSB 1 - , BSB 2 - and BSB 3 - are about 60dB and the saturation gain of 10km DCF forward pumped FRA is about 27dB, so the gain of FBA is about 33dB. The forward and backward cascaded SBS lines have been observed.