Light-Matter Coupling; Scanning Probe Lithography; 3D depth profiling; Microcavities; Light confinement
Ding Fei, Stoeferle Thilo, Mai L., Knoll Armin, Mahrt Rainer F. (2013), Vertical microcavities with high Q and strong lateral mode confinement, in Phys. Rev. B
, 87, 161116.
Garcia Ricardo, Knoll Armin, Riedo Elisa, Advanced scanning probe lithography, in Nature Nanotechnology
, 9, 577-587.
Knoll Armin, Zientek Michal, Cheong Lin Lee, Rawling Colin, Paul Philip, Holzner Felix, Coady Daniel, Hedrik James, Allen Robert, Duerig Urs, Closed-loop high-speed 3D thermal probe nanolithography, in Proceedings SPIE
, Alternative Lithographic Technologies VI.
During the last project entitled “Surface structuring by means of stimulated desorption of organic material” we have achieved two important milestones. The first relates to a precise fabrication of three dimensional patterns by thermal Scanning Probe Lithography (tSPL), and the second involves the directed assembly of nano-particles with 10 nm precision. Here we propose to combine the two achievements in order to fabricate novel optical micro-cavities with high performance and optimal integration of optically active nano-particles. The three-dimensional fabrication method is used to produce mesas in the spacer layer of a vertical Fabry-Perot type microcavity. The mesas are produced in a way that the optical cavity modes are localized within the mesa structure thereby achieving low effective mode volumes. Furthermore the mesa is designed as a three dimensional “rounded” structure which minimizes scattering of light into other cavity modes. The mesa outline can be designed into almost arbitrary shapes just limited by the shape of the scanning probe tip. One goal of the proposed project is to optimize the mesa design to achieve optimal light confinement in low loss cavities. A second aspect of this proposal is the deposition of optically active nano-particles at predefined positions within the microcavity. The particles can be examined after deposition to select the ones fitting best to the desired cavity response. The particles can be detected using the tSPL tool in the imaging mode. Using the same tip the light confining mesa structure can be written in precise registry with the selected nano-particle. This allows for a designed coupling of one or potentially more nano-particles to a cavity mode. The strength of the coupling will depend on the quality of the fabrication process. However, preliminary simulation results indicate that the rounded mesas and the particle placement strategy will provide superior performance in comparison to existing designs. This makes us confident that we will be able to study light-matter coupling effects like enhanced/suppressed spontaneous emission or non-linear optical effects. Furthermore the new fabrication process may potentially allow us to explore the coupling of multiple dots to the same cavity. Depending on the achievable coupling strength nanophotonic applications like low threshold lasing, single photon sources or other quantum information devices are within reach.