Generation And Regulation Of The Microcavity Soliton Microcomb

Optical microcavities have gained widespread attention due to their small mode size and high quality factor,which significantly enhances the interaction between light and matter.They have found applications in several fields including cavity quantum electrodynamics,microcavity lasers and biochemical sensing,microcavity optical frequency combs,cavity photomechanics,and nonlinear optics.By balancing dispersion and nonlinearity,gain and loss,the dissipative Kerr soliton with low noise,coherence and mode-locking can be generated in the microcavity.Compared with traditional mode-locked lasers,the soliton microcomb has the advantages of miniaturization,low power consumption,controllable dispersion,high repetition rate,wideband spectrum,etc.,showing great potential in optical ranging,coherent optical communication,astronomical optics,microwave photonics,precision spectroscopy and other applications.Although there has been a lot of exploration in the physical mechanism and photonics application of the microcavity soliton microcomb,there are still some problems to be solved.For example,the generation and stability of the microcavity soliton microcomb,the conversion efficiency is low,the spectrum range is limited by material dispersion,and other nonlinear dynamics in the microcavity still need to be explored.This paper carries out relevant research around these problems.The generation and regulation of soliton microcombs are realized in different microcavity systems.Based on other nonlinear effects in the microcavity,the spectrum of the microcomb is extended,and the conversion efficiency is improved.Frequency locking of two microcavity systems is realized by injection locking.The main content of this paper is divided into the following aspects:1.The generation and regulation of the soliton microcomb in the silicon nitride microring,and Raman assisted soliton microcomb with high conversion efficiency in the silica microsphere are demonstrated.The optical mode and dispersion of silicon nitride microrings with high quality factor are characterized.In the silicon nitride microring with anomalous dispersion,dissipative Kerr solitons are generated,the spectral range can reach 150 nm.The perfect soliton crystal with controllable number of solitons is realized,based on the tuning of pump intensity to avoided mode crossings.This method of thermal tuning is universal and can be extended to other platforms,while facilitating the application of perfect soliton crystals.Based on Raman gain,the soliton microcomb with conversion efficiency up to 20.8%is generated in the silica microsphere,which achieves high output.2.For the first time in the world,the generation of the single soliton in silicon carbide microdisk at room temperature is realized,and the optical frequency comb is transferred from infrared to visible band.We demonstrate,for the first time in the world,perfect soliton crystals,two-solitons and the single soliton have been realized in the silicon carbide microdisk with high quality factor at room temperature,by introducing an auxiliary laser to balance the thermal effect.Based on the second harmonic generation and sum frequency generation,the wide spectrum conversion from near infrared to visible band of microcavity optical frequency comb is realized.This kind of spectral conversion from near infrared to visible band is of great significance to the future application of optical frequency comb technology in spectroscopy and the realization of self-reference.3.Based on injection locking,the frequency locking between the breathing soliton and the mechanical oscillator with different physical mechanisms is proposed and realized.Based on the breathing frequency of the breathing soliton in a silicon nitride microring,the mechanical mode with similar frequency is found in a silicon microdisk.The resulting mechanical oscillation is loaded onto the pump laser,the breathing frequency and the mechanical frequency are locked by injection locking.When the frequency is locked,the ultra-narrow linewidth and low noise characteristics of themechanical oscillator are transferred to the breathing soliton successfully,the stability of the system is significantly improved.Our results provide a new way for the stabilization and control of the breathing soliton,and may inspire the study of the interaction between the mechanical oscillator and the breathing soliton.4.A new physical mechanism of all-optical synchronization of optomechanical systems is proposed and realized.By combining injection locking and synchronization,the synchronization of two remote optomechanical systems is realized.Based on the thermal-optic and optical spring effect,we overcome the challenges in the simultaneous alignment of both the optical and mechanical modes in different optomechanical systems.A pump laser is used to drive the silica microsphere,the residual pumped laser and the generated sideband are guided into the silicon microdisk through a 5 km-long single-mode fiber.The mechanism of injection locking and synchronization are combined to realize the remote all-optical synchronization,and the synchronization frequency is not limited by the bandwidth of the device during transmission.The remote all-optical synchronization technology demonstrated in this experiment is expected to use the existing optical fiber network to build a complex synchronous system network,which is expected to be applied in the fields of clock synchronization and optical communication.