Dr. A. F. Koenderink
FOM Institute AMOLF
Center for Nanophotonics
Research Interest
Current research direction
Research carried out at the FOM Institute AMOLF
Funded by:
VIDI innovational research grand (NWO)
FOM Projectruimte
FOM Programs on Plasmonics and Nanoscale Quantum Optics
NanoNed
NanoNextNL
Why ?
Photonics revolves around the complete control of emission and transport of light in ultrasmall structures. Such control over photons promises to revolutionize quantum optics, information processing, communications, and data storage.
Ultimately, the size limit for confining photons is set by the wavelength of light. The key to overcome this limit is to transfer optical energy to antenna structures that are formed from resonant scatterers, like atoms, or nanoparticles such as quantum dots, metal plasmon particles, or magneto-electric scatterers like split rings, that form the basis of metamaterials.
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Why fascinating ?
Since the spacing of 25-100 nm is considerably smaller than the wavelength one generally assumes that a near-field, or quasistatic limit applies, in which interference and phase differences. Instead, we've found that phase retardation, radiation damping and significant beyond-nearest-neighbor coupling between particles conspire to produce complex interference effects in hopping transport, and significantly modify the dispersion relation for guiding signals. One remarkable consequence that was recently predicted for collectively excited plasmon particle arrays is that electromagnetic energy can become strongly localized on individual scatterers, where small changes in driving frequency completely change the spatial distribution on a sub-wavelength scale. Such tunable nanoscale confinement of electromagnetic energy is a fingerprint of the rich physics of hopping transport in taylored geometries of resonant coupled particle arrays.
Main questions that my current research addresses:
What is the smallest resonant solid state building block for optical circuits ?
How do we engineer the coherences and far-field coupling between components to build the smallest functional optical circuits ?
How can we optimize far-field coupling as in microwave multi-element antennas to obtain optimum funneling of light onto the nanoscale ?
How can we interface single photons and single emitters to far field beams with unit efficiency for capturing the emitted photons, and conversely unit efficiency for absorbing single photon wavepackets ?
Research expertise from 2000 - present
My research has focused on novel photonic systems, aimed at solid-state quantum optics and novel optoelectronic devices. The three main recurring themes are:
(I) Spontaneous emission control & local density of states. In my PhD research (1999-2003) we [1] were the first to demonstrate broadband inhibition of spontaneous emission in 3D photonic crystals. Research at ETH (2003-2005) established the potential of 2D photonic crystal membranes for emission control and the possibility of on-demand variation of emission rates of sources that are manipulated with near-field scanning probe methods [2].
(II) Transport and scattering by disorder in ordered photonic materials. New types of experiments revealed striking properties of multiple random scattering in photonic crystals [3,4], demonstrating new opportunities in the fields of multiple scattering and Anderson localization. On the other hand, a realistic but critical assessment of losses has exposed intrinsic fabrication inaccuracies as a major threat to realizing proposed photonic crystal integrated circuits [5].
(III) Tuning and switching photonic materials. At the University of Amsterdam (2002), I co-developed a proposal to switch photonic bandgaps via refractive index changes induced by two-photon excitation of free carriers [6]. In contrast to this global switching, in research at ETH I focused on scanning probe methods for local tuning of individual high-Q resonances in photonic crystals. This research combined a strong theoretical component [7] with near-field optical microscopy on waveguides and high-Q cavities.
Research techniques
Experimental techniques
• Scanning near-field optical microscopy (shear-force)
• Scanning near-field optical microscopy (cantilever probes)
• Confocal microscopy
• Confocal IR fluorescence microscopy
• Time-correlated single-photon counting methods
• Fourier-Transform white light spectroscopy
• Far-field fluorescence
- • Diffuse escape function & coherent backscattering measurements
Numerical techniques
• Exact point-dipole models
• Plane-wave LDOS and bandstructure calculation
• 3D FDTD simulation
• Fourier-modal layered grating calculations
• Dyadic Green's function theory