Chen Mo, Meng Zhou, Sun Qiao, Sun Shilin, Tu Xiaobo
Opt Express. 2014 Jun 16;22(12):15039-48. doi: 10.1364/OE.22.015039.
A fast-tuning Brillouin/erbium fiber laser (BEFL) is investigated on its mechanism and characteristics in detail, in which a 4 m erbium-doped fiber (EDF) as both the Brillouin gain and linear gain media is coiled on a piezoelectric transducer (PZT) for laser frequency modulations. We demonstrate the fast-tuning mechanism theoretically and experimentally that only the lasing cavity mode is modulated, instead of the previous presumption that the Brillouin frequency shift of the EDF is modulated synchronously with the lasing mode. And the maximum tuning range (~60 MHz) is limited by the bandwidth of the Brillouin gain spectrum. The frequency tuning amplitude is direct proportional to the voltage on the PZT. The tuning rates reach up to 48 kHz. The BEFL keeps high-coherence property under fast frequency modulation. Its phase noise remains about -124 dB/Hz1/2 (normalized to 1 m optical path difference) at 1 kHz under 32 kHz modulations. This fast-tuning BEFL presents a wide range of applications in fiber sensors, optical fiber communications, and so forth.
对一种快速调谐的布里渊/掺铒光纤激光器（BEFL）的机理和特性进行了详细研究，其中，一段4米长的掺铒光纤（EDF）既作为布里渊增益介质又作为线性增益介质，缠绕在一个压电换能器（PZT）上用于激光频率调制。我们通过理论和实验证明了快速调谐机理，即仅对激光腔模进行调制，而不是像之前推测的那样，EDF的布里渊频移与激光模式同步调制。并且最大调谐范围（约60兆赫）受布里渊增益谱带宽限制。频率调谐幅度与PZT上的电压成正比。调谐速率高达48千赫。BEFL在快速频率调制下保持高相干特性。在32千赫调制下，其在1千赫时的相位噪声在归一化到1米光程差时仍保持在约 -124分贝/赫兹1/2 。这种快速调谐的BEFL在光纤传感器、光纤通信等领域有广泛应用。
