Search results for "optical tuning"
showing 4 items of 4 documents
In situ tuning of a photonic band gap with laser pulses
2008
We report on light-induced optical tuning of colloidal photonic crystals doped with gold nanoparticles (Au-nps). By resonantly exciting the Au-np surface plasmon absorption with picosecond pulses at 0.53 micron in a standard pump-probe setup, we observed permanent changes in the stop band resonance around 1.7 micron, with blue wavelength shifts as large as 30 nm and associated to a nanoparticle reshaping. Fine tuning was achieved by controlling either the pulse energy or the irradiation time.
Optical tuning of dielectric nanoantennas for thermo-optically reconfigurable nonlinear metasurfaces
2021
We demonstrate optically tunable control of second-harmonic generation in all-dielectric nanoantennas: by using a control beam that is absorbed by the nanoresonator, we thermo-optically change the refractive index of the radiating element to modulate the amplitude of the second-harmonic signal. For a moderate temperature increase of roughly 40 K, modulation of the efficiency up to 60% is demonstrated; this large tunability of the single meta-atom response paves the way to exciting avenues for reconfigurable homogeneous and heterogeneous metasurfaces.
Fine tuning of a photonic band-gap with picosecond laser pulses
2008
We report on light-driven tuning of the optical properties of colloidal photonic crystals (polystyrene opals) doped with gold nanoparticles (Au-np). Using picosecond pulses at 532 nm we obtained permanent changes in the stop band around 1700 nm, with resonance blue shifts as large as 30 nm.
All-optical tuning of a photonic band-gap via near-infrared laser pulses
2008
We present an all-optical tuning at IR wavelength in a novel photonic crystal consisting of a polystyrene opal with gold nanoparticles. The band-gap can be finely tuned with permanent shifts as large as 30 nm irradiating the sample with ps pulses at a low rep-rate in the visible.