Experimental research on single-frequency fiber Raman amplifier

Abstract

Single-frequency fiber Raman amplifier (SF-FRA) is known for the ability of all-band amplification, and it is very attractive for the amplification of single-frequency seed light at a special wavelength, such as 1178nm and 1271nm. The 1080nm single-frequency signal light is amplified by a 1031nm pump source, and the influences of seed power of single-frequency signal light, length of Raman gain fiber, pump scheme are experimentally investigated. The results show that the efficiency of SF-FRA increases with the enhancement of the single-frequency signal power and the length of Raman gain fiber. The efficiency of co-pump SF-FRA is higher than that of the counter-pump SF-FRA. The measure ments show that the linewidth of single-frequency signal light is not broadened obviously in the process of Raman amplification. The visibilities of the rapid-exposure pattern of far-field interference of single-frequency seed light and the amplified light are 0.814 and 0.719, respectively. The results show that the coherence of single-frequency signal light is affected by the SF-FRA more or less. These experimental results can provide a reference for designing other special wavelength SF-FRA.