Ultrafast nonlinear absorption of TMDC quantum dots

Comment on "Coherent nonlinear optical response of single quantum dots studied by ultrafast near-field spectroscopy".

The nonlinear response of single GaAs quantum dots is studied in femtosecond near-field pump-probe experiments. At negative time delays, transient reflectivity spectra show pronounced oscillatory structure around the quantum dot exciton line, providing the first evidence for a perturbed free induction decay of the excitonic polarization. Phase-disturbing Coulomb interactions between the exciton...

Ultrafast Nonlinear Optical Response in GaN/AlN Quantum Dots for Optical Switching

Ultrafast Nonlinear Optical Response in GaN/AlN Quantum Dots for Optical Switching Applications at 1.55 μm

Multi-terabit optical time division multiplexing (OTDM) networks require semiconductor all-optical switches and wavelength converters operating at room temperature. These devices should be characterized by AN ultrafast response capable of sustaining high repetition rates with low switching energy and high contrast ratio. These features lead to consider the use of resonant nonlinearities for the...

Two-photon absorption in CdTe quantum dots.

We report measurements of frequency degenerate and nondegenerate two-photon absorption (2PA) spectra of CdTe quantum dots, QDs, in glass matrices and compare them with 2PA in bulk CdTe. We find that the 2PA is strongly dependent on the size of the QDs becoming smaller with decreasing size, even when normalizing to the volume of the dots. We adapt a simple degenerate 2PA model, based on the effe...

Ultrafast population switching of quantum dots in a structured vacuum.

We demonstrate picosecond, high-contrast population flipping of two-level atoms interacting with femtojoule optical pulses in a 3D photonic band gap waveguide. This is the result of giant Mollow splitting caused by strong light localization and a remarkable field-dependent relaxation of the atomic Bloch vector as it evolves near an abrupt jump in the electromagnetic density of states. Unlike st...