Research On Dissipative Kerr Soliton Based On High Performance Optical Microcavity

The capacity of fiber transmission network is developing towards Terabit or even Petabit,with the sustained,rapid growth of all kinds of communication services.One of the key technologies supporting this march is the novel light source which suites to large capacity optical transmission system.The newly invented microcavity-based Kerr comb has the unique advantages of high performance and chip-scale integratable,which shows its prominent potential to become the next generation light source.By means of optical parametric oscillation,cascade four-wave mixing and dissipative soliton generation,the Kerr optical comb technique based on optical microcavity generates ultra-wideband comb spectra and ultra-short pulse waveforms in microcavity.Compared with conventional frequency comb based on femtosecond mode-locked lasers,Kerr comb features substantially compacted volume,high repetition rate,low power consumption,and possible for on-chip integration.Thus,Kerr comb has been considered as the most potential technique for next-generation frequency comb devices.And with the gradual maturity of micro-nano processing technology,optical microcavity has been developed rapidly.Optical microcavity has become an important basic device in the field of nonlinear optics due to its advantages of ultra-high-quality factor(Q),high efficient optical field limitation,rich material selection,flexible structure regulation,and on-chip integration.Therefore,the optical frequency comb technology based on optical microcavity can be applied to more fields.For this research background,this dissertation is based on optical microcavity,the systematic research involving from the preparation of high-performance optical microcavity and the generation of DKS combs in high-performance optical microcavities to the DKS energy conversion efficiency and DKS pulse time jitter based on optical microcavity has been carried out.The research contents and innovations are as follows:1.The design,fabrication,and free spectral range(FSR)optimization of high-performance optical microcavity are studied.The simulation mode of optical microcavity,which is used to optimize dispersion,Q factor,and mode distribution,is established.Based on the simulation results,the high-performance silicon nitride microring cavity and quartz whispering gallery mode(WGM)microrod cavity are fabricated.On this basis,innovative processes such as fine laser melting,surface defect control and laser annealing are proposed,and Q value improvement,mode control and FSR optimization of optical microcavity are realized.2.The nonlinear effect in optical microcavity is studied.Different methods to generate soliton Kerr comb is experimentally studied,including auxiliary laser heating method,common auxiliary laser heating method.By using such techniques,the generation of low noise soliton combs in silicon nitride microring and quartz WGM microrod cavity is achieved.In addition,the soliton mode-locked optical comb stability enhancement technology is studied.Through micro-cavity optical packaging,pumped laser polarization state dynamic modulation,frequency detuning feedback,and other technologies,the soliton optical comb has successfully achieved stable operation for 14days.The deterministic single DKS burst in an optical microcavity are demonstrated for the first time.3.The energy conversion efficiency of DKS in optical microcavity is studied.Aiming at the extremely low energy conversion efficiency between the ultra-short soliton pulse and the pump laser in the microcavity,which leads to the serious shortage of the Kerr optical comb spectral line power,a new high-performance optical microcavity witn low nonlinear,low loss,and high coupling coefficient microcavity is proposed to improve the energy conversion efficiency of DKS.By optimizing the parameters of the microcavity,the microcavity with Q value greater than 10~8 is successfully prepared,and the DKS energy conversion efficiency is improved by 20%.4.The time jitter of DKS pulse in optical microcavity is studied.In view of the high sensitivity of DKS physical system to the random jitter of system parameters,which leads to the time jitter of soliton pulses.A soliton shaping scheme is proposed to suppress Raman self-frequency shift and dispersion wave,and the time jitter of soliton pulse is suppressed.The time jitter performance of soliton pulse in optical microcavity is approached to the quantum noise limit.