Reserch Of Graphene-enhanced All-fiber Resonator Lasers And Sensors

Since its inception,graphene has been favored for its natural advantages such as ultra-high carrier mobility,ultra-high surface-to-volume ratio,ultra-fast thermal conductivity,excellent electro-optical tunability,and excellent bioaffinity.It has been received widespread and in-depth research by scientific researchers around the world.It is worth mentioning that the successive introduction of graphene-based enhanced optoelectronic information devices has brought revolutionary changes to contemporary ultra-high-speed optical communication and intelligence sensing.The combination of the excellent two-dimensional material and information devices,will strongly promote the development of information communication,environmental monitoring,medical diagnosis and other fields.Under the above background,the concept of "Lab On Fiber" provides new ideas for the expansion of graphene applications.It integrates high-quality single-atom-thick twodimensional graphene film materials inside the all-fiber resonator.The cavity provides the optical energy efficiency of the device,and at the same time,graphene significantly enhances the interaction between light and matter,and uses the excellent characteristics of graphene to greatly improve the optical performance of the device.This thesis is based on the all-fiber resonator structure,using high-quality graphene and its derivatives with remarkable optoelectronic tunability,excellent biocompatibility and fluorescent resonance energy transfer and other characteristics,contributing both as biochemical sensing platforms and adjustable modules to achieve ultra-high-sensitivity selective biochemical molecular photodetection and high-repetition frequency laser comb.In summary,the work of this thesis is mainly divided into the following four parts:(1)The current research status of graphene at home and abroad is systematically investigated.The development status of optical microstructure sensors,ultrafast lasers,and optical frequency comb devices are reviewed.At the same time,the development and application of graphene-based fiber information devices are reviewed.For the scientific problems in the development of graphene based ultra-high-sensitivity biochemical sensors and ultra-fast lasers,the research significance of this topic is proposed.(2)The photoelectronic characteristics of graphene materials and the working principle of fiber resonators are systematically explained.The preparation and processing technology of all-fiber resonators,the preparation of graphene and its derivatives,and the method of deviceization transfer are introduced in detail.The graphene-enhanced fiber Fabry-Perot microcavity biochemcial sensor and graphene-based all-fiber Fabry-Perot cavity frequency comb device was introduced in detail in the preparation process and characterization test.(3)A graphene-enhanced biochemical microfiber resonator with individual molecule sensitivity and selectivity was proposed and implemented.The sensor was functionalized in three different ways,using the fluorescent resonance energy transfer characteristics of graphene oxide and biochemical tunability,to achieve selective sensing of dopamine molecules,nicotine molecules,and single-stranded DNA molecules.Moreover,by measuring the intermode interference via noise canceled beat notes and locked-in detection combined with high-sensitivity photoelectric heterodyne detection methods,we achieved the real-time dynamic detection and individual molecule sensitivity.(4)An all-fiber graphene electrically controllable high-repetition laser frequency comb device was proposed and implemented.By integrating the gold-graphene-gold heterostructure on the end face of the fiber,the external electrical modulation was used to precisely control the Fermi level.The graphene heterostructure contributed both as the tunable absorber,the controllable dispersion delay,and the fast OE feedback stabilizer simulataneously.Here,We demonstrate a graphene hterogeneous fiber laser microresontor,realizing both high repetition soliton-locked frequency combs(spectrum span 1300 nm to 1800 nm,repetition rate ranging from 9.72 GHz to 77.8 GHz,picosecond pulses)and high precision electrical controllability.