Simulation, Design And Preparation Of Glass Micro/Nanoifbers With Nanocore And Cladding Structure

Compared with traditional optical fibers, micro/nanofibers (MNFs), also called sub-wavelengthdiameter fibers, exhibit a series of interesting properties, including small sizes, low optical loss,large mode area evanescent wave, large wave dispersions, being bended easily and so on, whichhave wide applications in fiber communication, fiber sensing, and nonlinear optics. At present, themethods to fabricate MNFs mainly include two steps tip stretching, chemical synthesis and laserablation, while those fibers have no cladding and are too short to realize large-scale production.Therefore, it is significant to research on ultra-long glass MNFs which not only have the structureof nanocore and protective cladding, but also can be drew wholesale. So the aim in this paper is todesign and fabricate glass MNFs with nanocore and cladding structure in theory and experimentsection.In theory section, it is studied that the single mode and optical waveguiding characteristics,through the model simulation and numerical analysis. The results show that the subwavelength coreof MNFs can keep the single mode properties with the large difference of the refractive indicesbetween the core and the cladding, but too much difference may narrow the optional range of thecore diameter, so the suitable refractive index difference are very important for the waveguidingtransmission in MNFs. And it is found that more and more energy in MNFs are diffused into thecladding with the decrease of the core diameter.In experiment section, it is preparaed the phosphate glass for the core and Yb3+-dopedphosphate glass for the cladding. Then the preform, drawing, cutting and polishing process of glassMNFs are studied. It is successed to prepare glass MNFs with nanocore and cladding structure,using the casing method and the multi steps drawing method.