Optical Sciences

Biomolecules and nanostructures

The Optical Sciences group studies the interaction of light and matter. Our current focus is on detection and sensing/imaging with an emphasis on the development of integrated photonics. We are part of Twente University's Department of Science and Technology and member of the MESA+ institute.


Real-Space Observation of Ultraslow Light in Photonic Crystal Waveguides

(full pdf)

H. Gersen, T. J. Karle, R. J. P. Engelen, W. Bogaerts, J. P. Korterik, N. F. van Hulst, T. F. Krauss, and L. Kuipers
Physical Review Letters
vol 94 p073903 feb 25 2005

We show the real-space observation of fast and slow pulses propagating inside a photonic crystal waveguide by time-resolved near-field scanning optical microscopy. Local phase and group velocities of modes are measured. For a specific optical frequency we observe a localized pattern associated with a flat band in the dispersion diagram. During at least 3 ps, movement of this field is hardly discernible: its group velocity would be at most c/1000. The huge trapping times without the use of a cavity reveal new perspectives for dispersion and time control within photonic crystals. copyright 2005 The American Physical Society

This article features the following (EPAPS) movies:
Gersen_et_al_PRL_EPAPS_fig2.avi (1392.0 kB)
Gersen_et_al_PRL_EPAPS_fig2_with_high_resolution.tiff (4013.2 kB)
Gersen_et_al_PRL_EPAPS_fig4.avi (3272.0 kB)
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