### Single object and single emitter nanoscopy

Working with single nano-antennas and single quantum emitters directly implies a strong interest in nanoscopy, and nano-manipulation. Questions one immediately ask are for instance: how do you select an excellent emitter on basis of its photophysical properties, how do you position one object relative to the other via chance, lithography, or nanomechanical manipulation, and what are the scattering properties of single objects. A workhorse tool in our group is single molecule fluorescence microscopy. Using state of the art methods, one can nowadays measure the spectrum and lifetime of a single emitter within 10 ms, meaning that one can really follow changes in photophysics in time. Superresolution and NSOM techniques can be used for localizing single objects relative to each other. In our work, we focus on applying such techniques to light-matter interaction problems. Examples are measuring Purcell factors as function of spatial coordinate with superresolution, measuring the intrinsic quantum efficiency of single emitters, and measuring emission properties while you make geometrical changes to a resonant nanostructure.|

### Fourier microscopy - amplitude, vector and phase mapping of radiation patterns

Resolving angles in microscopy is at least as informative as resolving space. What is the distribution of scattering or of photon emission over angle? In the fields of plasmonics and metamaterials,
intuition very often relies on classifying a structure as a dipole, multipole, magnetic moment, as having chiral contributions, or as being a coherent interfering sum of terms.
Quantifying this intuition is difficult as one can not actually *measure* induced multipole moments. Alternatively, one *can* measure the amplitude, polarization,
and phase of the light that a single nano-objecct emits or radiates into each solid angle in principle is sufficient information. We use so-called `Fourier’ microscopy, to measure radiation
patterns in the backfocal plane of microscope objectives to quantify radiation patterns, polarizations, and in future phase. We apply this method to plasmon antennas that beam fluorescence,
to plasmon lattice phosphors and lasers, and to antennas that impart chirality, and orbital angular momentum, to emitted light.

Single emitter microscopy:

[88] | K. Guo, M. A. Verschuuren, and A. F. Koenderink, , Optica Superresolution Imaging of the Local Density of States in Plasmon
Lattices3, 289–298, (2016). |
(p)reprint DOI |

[86] | F. T. Rabouw, N. M. B. Cogan, A. C. Berends, W. van der Stam, D. Vanmaekelbergh, A. F. Koenderink, T. D. Krauss, and C. de M. Donega, , Sci. Rep. Non-Blinking Single-Photon Emitters in Silica6, 21187, (2016). |
(p)reprint DOI |

[81] | F. T. Rabouw, M. Kamp, R. J. A. van Dijk-Moes, D. R. Gamelin, A. F. Koenderink, A. Meijerink, and D. Vanmaekelbergh, , Nano Lett. Delayed Exciton Emission and Its Relation to Blinking in CdSe Quantum
Dots15, 7718–7725, (2015). |
(p)reprint DOI |

[78] | F. T. Rabouw, R. Vaxenburg, A. A. Bakulin, R. J. A. van Dijk-Moes, H. J. Bakker, A. Rodina, E. Lifshitz, A. L. Efros, A. F. Koenderink, and D. Vanmaekelbergh, , ACS Nano Dynamics of Intraband and Interband Auger Processes in Colloidal
Core-Shell Quantum Dots9, 10366–10376, (2015). |
(p)reprint DOI |

[62] | F. T. Rabouw, P. Lunnemann, R. J. A. van Dijk-Moes, M. Frimmer, F. Pietra, A. F. Koenderink, and D. Vanmaekelbergh, , Nano Lett. Reduced Auger Recombination in Single CdSe/CdS Nanorods By
One-Dimensional Electron Delocalization13, 4884–4892, (2013). |
(p)reprint DOI |

[61] | P. Lunnemann, F. T. Rabouw, R. J. A. van Dijk-Moes, F. Pietra, D. Vanmaekelbergh, and A. F. Koenderink, , ACS Nano Calibrating and Controlling the Quantum Efficiency Distribution Of
Inhomogeneously Broadened Quantum Rods by Using a Mirror Ball7, 5984–5992, (2013). |
(p)reprint DOI |

[58] | A. Mohtashami and A. F. Koenderink, , New. J. Phys. Suitability of Nanodiamond Nitrogen-Vacancy Centers for Spontaneous
Emission Control Experiments15, 043017, (2013). |
(p)reprint DOI |

[57] | M. Frimmer, A. Mohtashami, and A. F. Koenderink, , Appl. Phys. Lett. Nanomechanical Method to Gauge Emission Quantum Yield Applied To
Nitrogen-Vacancy Centers in Nanodiamond102, 121105, (2013). |
(p)reprint DOI |

Fourier microscopy:

[91] | A. H. Schokker and A. F. Koenderink, , Optica Lasing in Quasi-Periodic and Aperiodic Plasmon Lattices3, 686–693, (2016). |
(p)reprint DOI |

[87] | M. Cotrufo, C. I. Osorio, and A. F. Koenderink, , ACS Nano Spin-Dependent Emission from Arrays of Planar Chiral Nanoantennas Due To
Lattice and Localized Plasmon Resonances10, 3389–3397, (2016). |
(p)reprint DOI |

[84] | D. K. G. de Boer, M. A. Verschuuren, K. Guo, A. F. Koenderink, J. G. Rivas, and S. R.-K. Rodriguez, , Optics Express Directional Sideward Emission from Luminescent Plasmonic Nanostructures24, A388–A396, (2016). |
(p)reprint DOI |

[83] | C. I. Osorio, T. Coenen, B. J. M. Brenny, A. Polman, and A. F. Koenderink, , ACS Photonics Angle-Resolved Cathodoluminescence Imaging Polarimetry3, 147–154, (2016). |
(p)reprint DOI |

[82] | A. Mohtashami, C. I. Osorio, and A. F. Koenderink, , Phys. Rev. Appl. Angle-Resolved Polarimetry of Antenna-Mediated Fluorescence4, 054014, (2015). |
(p)reprint DOI |

[74] | C. I. Osorio, A. Mohtashami, and A. F. Koenderink, , Sci. Rep. K-Space Polarimetry of Bullseye Plasmon Antennas5, 9966, (2015). |
(p)reprint DOI |

[66] | T. Coenen, F. B. Arango, A. F. Koenderink, and A. Polman, , Nat. Commun. Directional Emission from a Single Plasmonic Scatterer5, 3250, (2014). |
(p)reprint DOI |

[42] | I. Sersic, C. Tuambilangana, and A. F. Koenderink, , New. J. Phys. Fourier Microscopy of Single Plasmonic Scatterers13, 083019, (2011). |
(p)reprint DOI |