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Coupling Nanowire Waveguides With Optical Fibers For Photonic Applications

Posted on:2013-10-12Degree:DoctorType:Dissertation
Country:ChinaCandidate:Y G MaFull Text:PDF
GTID:1228330395992944Subject:Optical Engineering
Abstract/Summary:PDF Full Text Request
The control and manipulation of photons on the subwavelength scale is one of the current trends in photonic devices. Nano optical waveguides, especially semiconductor nanowire waveguides, are promising nanostructures for2-dimensional tight confinement of propagating light, and have been attracting intensive interests for using as nanoscale building blocks for nanophotonic devices. Recent advances in plasmonics have made significant impact on the development of integrated photonics. Surface plasmon polariton waveguide have the inherent ability to break the diffraction limit and guide light on the deep subwavelength scale, and for both scientific study and practical application, optical connection by the nanofiber is a simple and efficient approaches. In this work, we have investigated the coupling between nanowire waveguides and optical nanofibers, and its applications in pigtailed semiconductor nanoribbon ring lasers and direct measurement of propagation loss of silver nanowires.As a typical nanowaveguide, semiconductor nanowires have advantages including easy fabrication, low loss, high gain, high nonlinearity and strong optical confinement. In the second chapter, we introduced the optical properties of semiconductors based on the guiding modes in a Zinc oxide nanowire. The polarization-dependent mode distribution and waveguide dispersion are studied. In the third chapter, we demonstrated the fabrication of a pigtailed semiconductor nanoribbon ring laser using a600nm wide and330nm thick CdS nanoribbon. When the20-um-diameter ring was irradiated by light from a supercontinuum source, multi-longitudinal mode laser emission was observed around523.5nm with a full widths at half maximum of0.27nm. The laser output from the pigtail showed strong orientation-dependent polarization, with a maximum polarization ratio of5and power up to3.7nW. The laser output power in this work is much higher than many other works reported previously.In the fourth chapter, we investigated the waveguiding properties of silver nanowires. We first introduced the basic concepts of surface plasmon polaritons (SPPs), followed by analytical calculation of the fundamental SPP mode of a silver nanowire waveguide. Then, we experimentally demonstrated a simple and direct measurement of propagation losses in single silver nanowires. Using a nanoscale fiber taper for highly efficient plasmonic excitation, propagation-length-dependent SPP waveguiding and output are measured with high accuracy and repeatability. The measured results of SPP propagation losses are0.64dB/μm (532nm),0.41dB/μm (633nm) and0.33dB/μm (980nm). respectively, which agree well with results from FEM analyses. The obtained propagation losses support previously reported indirect measurements, and indicate that the loss reported by previous theoretical calculations was overestimated.Overall, based on efficient coupling between nanowire waveguides and optical nanofibers, we have made important progress on efficient output of semiconductor nanoribbon ring lasers and propagation loss measurement of silver nanowires. The results demonstrated here may be helpful for future development of photonic and plasmonic devices based on semiconductor and metal nanowires.
Keywords/Search Tags:semiconductor nanowires, surface plasmon polaritons, ring resonator, ring laser, silvernanowires, SPP waveguide, propagation loss
PDF Full Text Request
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