The Photonic Forces group studies light-matter interactions, enhanced by confining photons to very small length scales for appreciable times. A strong focus is the coupling between light and motion in nano-optomechanical systems. Optical and acoustic degrees of freedom, both confined on the nanoscale in tiny optical cavities and vibrating mechanical structures, can strongly interact through radiation pressure forces. This allows extremely precise sensors, new photonic functionality, and control over the motional quantum state of a ‘macroscopic’ object.

Quantum measurement and control of mechanical motion

quantummeasurementThe intimate connection between precise measurements and control over the quantum state of a system is reflected in the notion that a strong measurement can directly affect a system by projecting it in an eigenstate. We study nanophotonic optomechanical systems that can serve as extremely sensitive and fast sensors of mechanical displacement. Using such displacement measurements, we aim to precisely control the quantum state of small mechanical objects.

Topological photons and phonons

topologyWe explore the links between broken symmetries and exotic transport properties, such as topologically protected one-way edge modes, in photonic and phononic lattices. Collaboration: Kobus Kuipers (TU Delft)

  • N. Parappurath, F. Alpeggiani, L. Kuipers, and Ewold Verhagen, Direct observation of topological edge states in silicon photonic crystals: spin, dispersion, and chiral routing, arXiv:1811.10739 (2018)
  • J. P. Mathew, J. d. Pino, and E. Verhagen, Synthetic gauge fields for phonon transport in a nano-optomechanical system,  Nat. Nanotechnol. (2020)

Optomechanical nonreciprocity

nonreciprocityWe study the breaking of Lorentz reciprocity, which stipulates that the transmission through a system is the same when the position of source and detector are interchanged. We exploit optomechanical interactions, which effectively break time-reversal symmetry for light. Collaboration: Andrea Alù (CUNY)


plasmomechanicsThe strength of radiation pressure forces scales inversely with the scale to which photons are confined. Ultimately strong optomechanical interactions are therefore enabled in plasmonic resonators, which allow squeezing light waves in deeply subwavelength dimensions. We investigate the use of such systems for broadband, practical nano-optomechanical sensors, reconfigurable photonic devices, and electro-optic conversion. Collaborations: Albert Polman and Tobias Kippenberg (EPFL)

Optical interactions in nanophotonic systems

phc_web2We try to understand nanophotonic functionality  such as emission enhancement, sensing, imaging, and polarization manipulation can be understood in terms of the system’s resonant eigenmodes. We study how concepts such as  energy conservation, reciprocity, and dissipation put fundamental bounds on functionality. In this context, we study hybrid plasmonic-photonic resonators and strongly chiral structures. Collaborations: Femius Koenderink, Kobus Kuipers (TU Delft)

Active optomechanics

activenanooptomechanicsWe investigate the advanced control over light, matter, and motion that can be achieved in tripartite systems where optical and mechanical modes are coupled to quantum emitters. Collaboration: Andrea Fiore (TU/e)

Past research projects:

Optical cooling and control of mechanical resonators in the quantum regime

quantumcoherentcouplingLaboratory of Photonics and Quantum Measurement, EPFL

Negative-index metamaterials based on plasmonic waveguides

negativeindexAMOLF (

Subwavelength nanofocusing of light with surface plasmons

nanofocusingAMOLF (

Enhancing absorption and emission with plasmonic resonators

coaxfluorescenceAMOLF (