Research And Frequency Measurement Of Stimulated Brillouin Scattering In Doped Silica Waveguides

As an important nonlinear optical phenomenon,stimulated Brillouin scattering(SBS)technology is widely used in the generation,processing,and storage of microwave photon signals.With the development of integrated manufacturing technology,the research on on-chip microwave photon processing technology has made great progresses.The Brillouin analog signal processing system based on traditional discrete platforms also faces the need for miniaturization and integration.The on-chip analog signal processing system based on SBS is composed of at least three parts: a miniaturized electro-optic modulation module,a chip used as an SBS medium,and a miniaturized data acquisition and processing module.In response to this need,this work analyzes and calibrates the SBS phenomenon on the doped silica waveguides,calculates and calibrates the SBS coefficient in the doped silica waveguides,and applies the simulation and experiment of instantaneous frequency measurement(IFM)based on SBS.This work contains the following three aspects:Firstly,the theoretical analysis of the SBS process in traditional fibers and the key parameters in the SBS process are introduced.The influence of the input signal wavelength and power on the SBS results is also analyzed.At the same time,the differences between the key parameters of SBS in the waveguides and the fibers are compared,and the effective transmission modes in the SBS process on the waveguides are simulated and analyzed.Secondly,the traditional Brillouin gain spectrum(BGS)measurement scheme is introduced,and its advantages and disadvantages are analyzed.Additionally,the traditional BGS measurement scheme is improved for the characteristics of short optical path,large loss,and serious reflection of the waveguide's end face.The improved BGS measurement system is used to observe the SBS phenomenon in the waveguides.By changing the parameters such as the input signal's wavelength and power,we explore their effects on the SBS effect.The Brillouin gain coefficient of the waveguides is calculated using a control experiment of single-mode fiber(SMF).The experimental results show that the SBS characteristics in the doped silica waveguides are consistent with the theoretical derivation.It is also found that more than one Brillouin gain peak exists in the doped silica waveguides,indicating that there are multiple effective transmission modes in the doped silica waveguides.Finally,based on the SBS-based IFM and fast IFM technology proposed by the research group in the early stage,SBS-based IFM experiments and simulations are performed on the doped silica waveguides to verify the feasibility of IFM on the waveguides.