Orthogonal Polarization Dual Kerr Soliton Frequency Comb Research Based On Pressure Sensitive Fiber Microresonator

The optical frequency comb is a revolutionary laser,which is essentially different from traditional light sources.It is composed of a group of frequency components that are locked to each other and equally spaced,and appear as periodic pulses in the time domain.Since winning the Nobel Prize in 2005,optical frequency combs have brought unprecedented new changes to the field of precision measurement with their unparalleled time-frequency accuracy.With the continuous improvement of sensing application range and measurement accuracy requirements,a series of dual-comb applications using dual optical frequency combs as signal sources,such as optical comb ranging and dual-comb spectroscopy,are booming.In practical applications,the coherence of dual-cavity dual-combs is far inferior to that of single-cavity dual-combs,and dual-combs in single-cavity often require the introduction of sub-pump lasers(Pump Laser,PL)or other modulators,increasing the System complexity and integrability.At the same time,the continuous development of dual-comb applications has put forward further requirements for dual optical frequency comb light sources.How to transition from dual-cavity dual-pump to single-cavity singlepump is a major scientific problem in realizing the integration of optical frequency combs.The subject of this work is "Research on Orthogonal Polarization Dual Kerr Soliton Frequency Comb Based on Pressure-Sensitive Fiber Micro-resonator",based on the structure of pressure-sensitive fiber Fabry-Pérot(FFP)micro-resonator,mainly Orthogonal dual Kerr soliton light source based on pressure-sensitive fiber microcavity and its extended application are explored.For the dual-soliton light source and application of functionalized frequency comb devices,a new scheme combining pressure-sensitive FFP microresonator and Kerr optical frequency comb excitation mechanism is proposed,which realizes single-cavity dual optical frequency comb excitation and expands its correlation.It provides a new solution with extremely low insertion loss for the buttcoupled all-fiber system.The specific contents of the research include:1.Research the basic theory of the pressure-sensitive FFP microresonator,and combine it with the Kerr microcavity-based soliton mode-locking theory to explore the excitation of BL in FFP as the second-order pump,and the first-order pump Simultaneous excitation of double Kerr solitons is theoretically established.Taking HNLF as the main body,a pressure-sensitive FFP microresonator cavity that can excite BL in an orthogonal polarization state was designed.The length of the fiber was obtained through accurate calculation,and a high-reflection film with a reflectivity as high as 99% was prepared at both ends of the fiber.A two-dimensional flexible and adjustable polarization controller is designed for the microcavity structure,and its temperature is kept constant by a metal cover.2.By applying the LLE(Lugiato-Lefever Equation)model,the excitation process of the optical soliton is studied,and through the birefringence effect(Bire Fringence Effect,BFE),the Brillouin laser and PL are obtained in the orthogonal polarization state.Pumped,dual Kerr solitons with a repetition rate of 1 GHz.Through the test and characterization analysis of dual-frequency comb spectrum,time-domain transmission spectrum and spectrum,its soliton characteristics are fully characterized.The coherence of soliton pairs is very high,and its phase noise can even reach-167 d Bc/Hz@1MHz.3.Utilize the pressure-sensitive characteristics of the FFP micro-resonator,and explore the sensitive linear response of the double-comb rich beat frequency signal to the pressure through the fine adjustment of the structural stress of the multi-connection rod.Its linear sensitivity is as high as 0.3k Hz/μN,and the measurement range Up to 7.3m N.It also expands the field of communication and sensing based on its pressure-sensitive characteristics,realizing the photonic microwave frequency regulation of 5G communication over 70 MHz and the ultra-high-sensitivity optical fiber stress detection with a resolution of 520 pN.