Study On Quantum Devices Based On Micro-/nanofiber

Quantum information is an interdiscipline of quantum mechanics and information science.It uses the principle of quantum mechanics of microscopic particles to solve the problems which are unsolvable in classical information science and classical computer science,and affords many exciting imaginations about future life.Due to the unconditional security,quantum communication becomes one of the most important applications of quantum information.Because of photon's weak interaction with environment,easy manipulation with linear optics and convenient transplantation of fiber communication technology,using photon as the information carrier and fiber as the information channel is the most widely adopted technology today to build quantum communication networks.In these quantum quantum communication networks,the quantum light sources and single photon detectors(SPDs)are the indispensable devices,and the effectivity and fidelity of the quantum systems both depend on the coupling efficiency between fiber and these devices.So,it could reduce the cost of the quantum systems significantly to generate high quality quantum sources directly from fiber and to fabricate SPDs which is lossless connected to fibers,and many research groups focus on them.Fortunately,optical micro/nanofibers(MNFs),with strong light confinement,enhanced evanescent fields,large waveguide dispersion and ultralow loss connected with standard communication fibers,may give a new platform to solve the problems above.It concludes 3 main parts in this paper:(1)The setup of MNFs pulling rig and the fabrication of high quality MNFs,with ultrahigh diameter control precision(<5nm),which is the record of all the reported result.(2)Fabricate ultralong waist length(?15cm)MNFs,and observate correlated photon pairs from them;to get higher purity photon pairs,further research of Raman noise in MNFs has been investigated.(3)Proposing a new type of superconducting nanowires single-photon detectors(SNSPDs)integrated with microfiber.The photons are guided by a microfiber and evanescently absorbed by the nanowires of SNSPDs when the nanowires are parallel and very close to the microfiber.The ongoing experiment's result shows a 51.6%system detection efficiency at 1064nm,which could be further improved by optimizing the refraction index of the cladding,diameter of the MNFs,alignment precision between the MNFs and nanowires,and the nanowire growth quality.Totally speaking,based on the fabrication of high quality micro/nanofiber with high control precision,we could set up correlated photon pairs generators and single-photon detectors,affording a potential solution to build all-fiber quantum commication networks.