Two-Photon Quantum Dot Excitation during Optical Trapping

Two-photon quantum dot excitation during optical trapping.

A single CW infrared laser beam can simultaneously trap and excite an individual colloidal quantum dot. Though the laser light is relatively weak, the excitation occurs through two-photon absorption. This finding eliminates the demand for an excitation light source in addition to a trapping laser in nanoscale experiments with simultaneous force-manipulation and quantum dot visualization. Also, ...

Optical Trapping and Two-Photon Excitation of Colloidal Quantum Dots Using Bowtie Apertures

We demonstrate bowtie apertures that were designed and fabricated by a lift-off process to optically trap individual, 30 nm, silica-coated quantum dots (scQD). Simulations and experiments confirm the trapping capability of the system with a relatively low continuous wave trapping flux of 1.56 MW/cm at 1064 nm. Additionally, the scQD emits upon trapping via two-photon excitation from the trappin...

Photon-Statistics Excitation Spectroscopy of a Quantum-Dot Micropillar Laser.

We introduce photon-statistics excitation spectroscopy and exemplarily apply it to a quantum-dot micropillar laser. Both the intensity and the photon number statistics of the emission from the micropillar show a strong dependence on the photon statistics of the light used for excitation of the sample. The results under coherent and pseudothermal excitation reveal that a description of the laser...

Two-photon Excitation of Quantum Dot Donors in Fluorescence Resonance Energy Transfer Applications

Excitation spectra of two correlated electrons in a quantum dot

Measurements and a theoretical interpretation of the excitation spectrum of a two-electron quantum dot fabricated on a parabolic Ga[Al] As quantum well are reported. Experimentally, excited states are found beyond the well-known lowest singletand triplet states. These states can be reproduced in an exact diagonalization calculation of a parabolic dot with moderate in-plane anisotropy. The calcu...