基于色散调控氟碲酸盐玻璃光纤的O-U波段平坦光频梳产生

O-U Band Flat Optical Frequency Comb Generation Based on Dispersion-controlled Fluorotellurite Glass Fiber

光学频率梳(简称光频梳)作为一种优秀的多波长光源在通信领域具有巨大的应用潜力。通过将光频梳光源与波分复用技术(WDM)、空分复用技术结合(SDM),通信系统可以具有百Tbit/s量级的传输速率,在5G/6G通信、物联网、自动驾驶等方面具有重要的应用价值。目前实现光频梳的方法主要有以下四种,分别为基于锁模激光器产生飞秒光频梳、基于光学微腔产生光频梳、基于电光调制器产生光频梳以及基于行波四波混频产生光频梳。它们各具特点,但均很难同时实现宽光谱、高信噪比、高平坦度、高的单梳齿功率以及梳齿频率间隔大范围可调,这在一定程度上影响了光频梳在光通信领域的应用。本文提出基于受激布里渊激光腔产生种子梳,采用腔外负色散光纤进行脉冲压缩,进一步利用色散调控的高非线性氟碲酸盐光纤进行扩谱,从而实现光频梳产生。数值计算结果表明,通过该系统,我们可以得到重复频率大范围可调、光谱覆盖整个O-U波段且在O-U波段梳齿强度标准差小于5 dB的平坦光频梳,证明了通过基于布里渊激光腔与色散调控高非线性氟碲酸盐光纤的光学系统产生可用于光通信的平坦光频梳的可行性。

Optical frequency comb(OFC)have great potential in the field of communication as an excellent multiwavelength light source.By combining OFC light source with wavelength-division-multiplexing(WDM)and spacedivision-multiplexing(SDM)technologies,the communication system can have a transmission rate in the order of a hundred Tbit/s,which is valuable in 5G/6G communications,Internet of Things,autonomous driving and many other aspects.At present,there are mainly four methods to obtain OFC,which are femtosecond OFC based on modelocked laser,OFC based on optical microcavity,OFC based on electric-optical modulator and OFC based on travel⁃ing wave four-wave mixing.All of them have their own characteristics,but all of them are hard to satisfy wide spec⁃trum,high signal-to-noise ratio,high flatness,high single comb power and wide range adjustable of comb spacing at the same time,which affected the application of OFC in the field of optical communication in some extent.In this pa⁃per,we put forward to get seed comb from stimulated Brillouin laser cavity,compress the pluse by negative disper⁃sion highly nonlinear fiber,and further on,widen the spectrum with dispersion-controlled fluorotellurite glass fiber,finally get OFC.The result of numerical simulation shows that,by using this system,we can obtin flat-top OFC with wide range adjustable comb spacing,spectral coverage the hole band form O-U,and the standard deviation of comb power in O-U band less than 5 dB,proved the feasibility of OFC generation based on system with stimulated Brillouin laser cavity and dispersion-controlled fluorotellurite glass fiber.