超稳光生微波源研究进展

随着科技的进步以及精密测量应用技术的不断提高,超稳微波源的稳定度和噪声水平等技术要求不断提高,应用范围愈加广泛,包括高性能频标研究、网络雷达研制、深空导航系统等方面.基于超稳激光和飞秒光梳的超稳光生微波源是目前频率稳定度最高的微波频率源,相对频率稳定度可达10~(16)@1 s量级.该装置也是未来频率标准(光频标)推广应用的基础,无论是时间的产生还是绝大多数的精密测量,都需要将光频标的输出激光变换为超稳的基带频率信号后才能够实现.本文介绍了超稳光生微波源技术的发展、现状和应用需求.以国家授时中心研制的国内首套超稳微波频率源技术为主线,介绍了超稳光生微波源的原理和结构以及各组成部分的技术发展情况:超稳激光方面,着重介绍超稳光学腔研究和研制的进展以及Pound-Drever-Hall锁频技术、剩余幅度调制等噪声抑制技术;飞秒光梳方面,着重介绍目前最常用的掺铒光纤光梳系统的激光锁模、频率控制等技术发展;低噪声光电探测方面,着重介绍宽带光电探测噪声抑制技术和激光幅度噪声引起微波相位噪声的抑制技术.最后对光生超稳微波技术进行了总结和展望.

Progresses of ultrastable optical-cavity-based microwave source

With the progress of science and technology and the continuous improvement of the precision measurement application technology, the technical requirements for the stability and noise level of the ultra-stable microwave source are increasing. Its application range becomes more and more wide, including high performance frequency standard research, network radar development, deep space navigation system, etc. Up to now, the photonic microwave generators based on ultra-stable laser and femtosecond light comb are believed to be the highest microwave frequency source with the highest frequency stability and the relative frequency stability 10^-16 in 1 s. This device is also the basis of the application for the next frequency standard (optical frequency standard). Whether the generation of time or most of the precision measurements, the output laser of the optical frequency standard should be transformed into a super stable baseband frequency signal. In this paper, we first introduce the development, current situation and application requirements of ultra-stable photonic microwave source, then we present the principle and structure of the ultra-stable photonic microwave source and the technical development of its components based on the first set of domestic-made ultra-stable microwave frequency sources developed by the National Time Service Center. For the ultra-stable laser, we mainly focus on the research and development of the ultra-stable cavity design, the Pound-Drever-Hall frequency locking technology, and the residual amplitude noise effect rejection. For the optical frequency combs, we mainly focus on the development of laser mode-locking and frequency control technology based on erbium-doped fiber combing system. For the low noise photonic-to-microwave detection and low noise synthesizer techniques, the noise effect rejection of wideband photoelectric detection and the microwave phase noise induced by the amplitude noise of the laser are emphatically introduced. Finally, we summarize and prospect the photonic ultra-stable microwave generation technique.