Transmission Of Quantum Information Based On Surface Plasmon Polariton Waveguide

Surface plasmon polariton has attracted more and more attention and research in the recent decades,owing to its ability to confine the electro-magnetic field to sub-wavelength scale near the metal-dielectric interface.The tightly confined optical modes can reduce the footprint of optical devices,improve the spatial resolution of optical sys-tems and enhance the interaction strength between photons and matters.However,the investigation on the quantum nature of surface plasmon polaritons has just got devel-oped in the last two decades,limited by the experimental techniques,mirco-nano fab-rication and electromagnetic field simulation.In the field of quantum information with photons,there are two blocks suffered from the drawbacks of photons.First,the diffrac-tion limited optical mode volume restrict the size of devices in micrometer scale,so it is hard to make circuits with large scale.Second,the ultra-weak interaction strength between photon and photon,photon and matter,cannot offer enough nonlinearity to perform quantum operations.Fortunately,surface plasmon polariton provides a viable solution to settle such problems.The ultra-small mode volume of surface plasmon po-lariton can increase the degree of integration and enhance the interaction between light and quantum emitters.My works mainly focused on transmission of quantum informa-tion in subwavelength plasmonic waveguide.This thesis mainly includes five parts in the following:1.We experimetally observed the Hong—Ou-Mandel interference between single surface plasmons in 600nm x 600nm dielectric loaded surface plasmon waveg-uide with world record visibility 95.7%at the telecom wavelength 1550nm.Our work demonstrated that quantilized surface plasmon polariton can be applied in the field of quantum information as well as photons.2.We investigated the effect of loss in the quantum photonic integrated linear cir-cuits.Generally,there are off-chip insertion loss and on-chip waveguide loss.Usually,people summarize all these linear losses and combine it with the ineffi-ciency of detectors.Since quantum processes can be realized via post-selection,which claims successful when detecting the photons in the desired manner,so linear quantum computation can still be performed with those imperfects,and the only influence is the low success probability.We studied the general loss mod-el in the on-chip beam splitter(BS)devices and its effects on the gate fidelities.We found that when there is unbalanced loss or shared common loss channel in the BS,there will significant errors that will affect the performance of the optical quantum processing.3.We studied the transmission of a photonic quantum-entangled state through a nanoscale hybrid plasmonic waveguide,composed of a silica-tapered fiber and a 160nm radius silver nanowire.The fiber integrated plasmonic probe can con-vert photons to surface plasmons adiabaticly with high efficiency and preserve the polarization of single photons,entanglement between different photons in the scale beyond the diffraction limit.4.The fluorescence of quantum dots are directly collected with a fiber integrated plasmonic probe,which avoids complex devices.The probe is promising to simultaneously realize the fluorescence enhancement,excitation and collection.5.We proposed a scheme to improve the estimation precision of loss with the cor-relation between photons and build a microscope to imaging highly transparent objectives with higher signal to noise ratio.The microscope can be combined with plasmonic probe to achieve super-resolution and super-sensitivity simulta-neously.