We present a new approach for the study of light propagation in 2-dimensional disordered lattices. We demonstrate experimentally diffusion-like transport and show by numerical study that our method can provide direct observation of Anderson Localization.
We experimentally demonstrate group velocity control of 40-fs, 1400-nm pulses through chi(2)-cascaded interactions under large group velocity mismatch. Group delay shifts up to 50 fs are achieved by propagation in a 25-mm-long PPSLT crystal.
An optical delay variable between 0 to 161 ps with GHz bandwidth is demonstrated in an InGaAsP quantum-well semiconductor optical amplifier and modeled by population oscillation and nearly degenerate four-wave-mixing effects for the first time.
We will give an overview of recently observed analogies between the transport of electrons and light waves and show how complex photonic materials, ranging from periodic to disordered structures can be applied as photonic devices.
Light propagation in slab photonic crystals can have a negative phase velocity and accumulate a negative optical path length. We present experimental results on guiding and dispersion properties when the phase index is approximately -1.
We present a new microscopy technique allowing electric field mapping in molecular media with micrometer resolution : electro-optical microscopy. We apply it to polymer devices and local measurements of transmembranar potentials in biomimetic membranes.
We present photon-spin quantum-state-transfer (QST) approach. GaAs/AlGaAs-QW with g~0 showed nonlinear B-field dependence of spin precession, suggesting photon-to-nuclei polarization transfer. 2DEG with quantum-point-contact on InGaAs/InP showed telecomwavelength-sensitive quantum transport. Efficient/high-fidelity QST conditions were also found.
We demonstrate dynamical nuclear spin polarization in single charged quantum dots without an applied external magnetic field. This is enabled by an effective magnetic field induced by the optically pumped spin polarized electron.
Stimulated THz emission from intra-excitonic 3p to 2s transitions in Cu2O is directly observed by ultrafast opto-electronics. The process occurs at a photon energy of 6.6 meV, with a cross section of ~10-14 cm2.
We demonstrate that optical solitons can exist in dispersion-inverted highly-nonlinear AlGaAs nanowires. These self-localized waves are possible at very low power levels in millimeter long nanowire structures.
Design considerations for quasi-planar, high-Q, silicon-on-insulator microphotonic resonators are presented. A figure of merit for use in comparison between microphotonic designs is presented and applied to compare existing and proposed designs.
Laser emission into modes of a dielectric microsphere was observed from optically pumped HgTe quantum dots on its surface. Including real-time measurement of the input pump losses reveals nanowatt threshold levels for these lasers.
We have demonstrated that two-photon absorption in a 2-cm-thick bulk GaP crystal can be the mechanism for limiting the efficient generation of the ultrafast broadband THz pulses using short infrared laser pulses.
We have detected electromagnetically-induced transparency (EIT) in a cigar-shaped MOT. The asymmetric shape of probe absorption as a function of frequency is consistent with enhancement of optical depth due to wave guiding of the probe.
We investigate coherent excitonic coupling in asymmetric double quantum wells with varying barrier thickness using optical two-dimensional Fourier transform spectroscopy. The coupling is isolated and characterized as cross peaks in two-dimensional spectra.
With 3-pulse wave-mixing ultrafast spectroscopy we probe simultaneously the intra and inter-band coherent dynamics in GaAs/AlGaAs quantum wells in a perpendicular magnetic field. By comparing to theory, we identify the role of inter-Landau-level coherences.
We have measured an optical Stark effect in semiconducting single-walled carbon nanotubes. Upon application of a non-resonant pump beam, we observe an instantaneous blue shift in the optical resonances that scales linearly with pump intensity.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.