高稳定单频Brillouin光纤激光器的研究

单频布里渊（Brillouin）光纤激光器结构紧凑,性能稳定,并且对Brillouin泵浦光具有线宽窄化和噪声抑制作用.在光纤传感、高精度频谱分析和微波光子学等领域有着重要应用前景.本文利用可调谐半导体激光器（TLS）作为Brillouin泵浦光制备了单频Brillouin光纤激光器.实验发现当Brillouin增益介质光纤的长度缩短到10.3m时,谐振腔的自由光谱范围变为20.1MHz与模光纤的Brillouin增益带宽相近,此时Brillouin激光表现为单纵模振荡.实验结果还表明该光纤激光器的功率转化斜率为43.6%,激光输出的强度涨落低于4%.单频Brillouin光纤激光器的信噪比与泵浦激光器的信噪比提高近10dB以上,并具有很好的噪声抑制作用,该激光器输出线宽小于5kHz.

Study on highly stable single-frequency Brillouin fiber laser

Single-frequency Brillouin fiber lasers （SF BFLs） have been attracting extensive interests because of their compact- ness, stableness and their characteristics of linewidth narrowing and noise suppression. They have important potential applications in many fields, such as fiber sensing systems, high-resolution spectroscopy and microwave photonics, and so on. In this paper, we demonstrated the SF BFL using the tunable laser source （TLS） as the Brillouin pump. When the cavity length is cut short to 10.3 m and the FSR is 20.1 MHz being comparable to the Brillouin gain linewidth, the BFL begins to operate in single-longitudinal-mode. The laser has the out power conversion efficiency of 42.5% and intensity fluctuation bellow 4%. The SF BFL＇s signal to noise ratio （SNR） is 10 dB greater than the TLS. Also, the laser has good performance for suppressing the noise and the linewidth of which is measured to be below 5 kHz.