摘要
以超冷铒原子系统冷却光的基频光作为探测光,主动补偿激发铒原子赫兹线宽能级跃迁的激光在光纤传输中引入的附加相位噪声。在不影响原有被传输亚赫兹线宽激光(1299 nm)的情况下,将相近波长的宽线宽基频光(1166 nm)从光纤输出端反向注入,实施外差拍频探测并主动反馈补偿。当两个波长激光的光纤传输噪声基本一致时,可极大地抑制亚赫兹线宽激光在光纤传输中由于温度和振动等因素引起的各种相位噪声。主动补偿后传输激光的线宽从锁定前的14.6 Hz压窄到锁定后的11.6 mHz,光频传输的1000 s稳定度从1.6×10^(-16)提升到6.5×10^(-19),满足当前最高精度和稳定度光钟的光频传输需求。所发展的光频传送方案可作为被传输激光器功率不足或空间受限时的替代方案,也可用在单点对多点近距离传输网络中简化源端发送装置。
The additional phase noise of a sub-Hz linewidth laser transmitted in the fiber to excite the Hz-linewidth transition of erbium is actively compensated for using the fundamental laser of the cooling laser in the ultracold erbium atom system.To perform heterodyne beat detection and implement the compensation feedback without affecting the power of the original sub-Hz linewidth laser(1299 nm),we injecte the broad-linewidth fundamental laser of the cooling light at a similar wavelength(1166 nm)from the output end of the fiber.The phase noise of the narrow-linewidth laser caused by temperature and vibration in fiber transmission is suppressed when the noise of the two lasers is almost the same.The linewidth of the beat frequency signal of the transmitted laser is narrowed from 14.6 Hz to 11.6 mHz and the stability of the optical-frequency transmission link is improved from 1.6×10^(-16) to 6.5×10^(-19) in 1000 s,meeting the optical-frequency transfer needs of a start-of-the-art optical clock.This optical-frequency transfer scheme can be used as an alternative where the power of the transmitted laser is insufficient or physical space is limited.The scheme is also applicable for simplifying the source setup on branching optical-fiber networks.
作者
廖文敏
张思慧
段玉青
王杰
武海斌
Liao Wenmin;Zhang Sihui;Duan Yuqing;Wang Jie;Wu Haibin(State Key Laboratory of Precision Spectroscopy,East China Normal University,Shanghai 200241,China)
出处
《激光与光电子学进展》
CSCD
北大核心
2024年第5期165-170,共6页
Laser & Optoelectronics Progress
基金
国家自然科学基金(11925401,11734008)
国家自然科学基金青年基金(12104158)。
关键词
光纤链路
光纤相位噪声
窄线宽
相位噪声抑制
光钟
fiber link
fiber phase noise
narrow linewidth
phase noise suppression
optical clock
