用于S波段光纤拉曼放大器增益平坦的长周期光纤光栅设计

Long-period Fiber Grating Using for Gain Flattening of S-band Fiber Raman Amplifier

根据实际所测得的S波段光纤拉曼放大器的信号增益谱,通过对长周期光纤光栅具体参数的选定,由两个长周期光纤光栅级联滤波的组合,可以使增益图谱在50 nm(1485-1535 nm)带宽内,增益平坦度达到±0.6dB以内.由三个长周期光纤光栅级联滤波组合,可以使增益图谱在49 nm(1490-1539 nm)带宽内,增益平坦度达到0.5 dB, 55 nm(1485-1540 nm)带宽内,增益平坦度达到1 dB.这对扩大长周期光纤光栅增益平坦滤波器的运用范围,扩大单泵浦S波段光纤拉曼放大器的有效增益带宽有着积极的意义.

In this paper, long period fiber gratings(LPFG) were used to flatten actually tested gain spectrum of single pumped S-band fiber Raman amplifier according to choosing proper parameters of grating. The filters with two LPFGs can make gain spectrum to realize ?.6 dB variation within 50 nm (1485-1535 nm) ,and the filters with three LPFGs can make gain spectrum to realize 0.5 dB variation within 49 nm (1495-1539 nm ) and 1 dB variation within 5 nm(1485-1540 nm). It is very significant for extending the range of gain flattening filter with LPFGs and extending the band-width of gain spectrum of single pumped fiber Raman amplifier.