New optical gating technique for detection of electric field waveforms with subpicosecond resolution.

The new optical gating technique uses a femtosecond optical laser pulses for the photoconductive detection of short pulses of terahertz (THz) radiation. This technique reproduces the shape of the THz pulse and after pulse plasmonic response of the two-dimensional electron gas in a short channel high electron mobility transistor (HEMT). The results are in excellent agreement with the electro-optic effect measurements and with the simulation results obtained in the frame of a two-dimensional hydrodynamic model.

Large excitonic enhancement of optical refrigeration in semiconductors.

We present a theoretical analysis for laser cooling of bulk GaAs based on a microscopic many-particle theory of absorption and luminescence of a partially ionized electron-hole plasma. Our cooling threshold analysis shows that, at low temperatures, the presence of the excitonic resonance in the luminescence is essential in competing against heating losses. The theory includes self-consistent energy renormalizations and line broadenings from both instantaneous mean-field and frequency-dependent carrier-carrier correlations, and it is applicable from the few-Kelvin regime to above room temperature.

Vacuum Rabi splitting with a single quantum dot in a photonic crystal nanocavity.

Cavity quantum electrodynamics (QED) systems allow the study of a variety of fundamental quantum-optics phenomena, such as entanglement, quantum decoherence and the quantum-classical boundary. Such systems also provide test beds for quantum information science. Nearly all strongly coupled cavity QED experiments have used a single atom in a high-quality-factor (high-Q) cavity.