Electrically injected photon-pair source at room temperature.

One of the main challenges for future quantum information technologies is the miniaturization and integration of high performance components in a single chip. In this context, electrically driven sources of nonclassical states of light have a clear advantage over optically driven ones. Here we demonstrate the first electrically driven semiconductor source of photon pairs working at room temperature and telecom wavelengths. The device is based on type-II intracavity spontaneous parametric down-conversion in an AlGaAs laser diode and generates pairs at 1.57 µm. Time-correlation measurements of the emitted pairs give an internal generation efficiency of 7×10(-11) pairs/injected electron. The capability of our platform to support the generation, manipulation, and detection of photons opens the way to the demonstration of massively parallel systems for complex quantum operations.

Nearly-degenerate three-wave mixing at 1.55 µm in oxidized AlGaAs waveguides.

We report on continuous-wave sum and difference frequency generation in selectively oxidized AlGaAs waveguides designed for degenerate spontaneous parametric down-conversion at 1.55 µm. Sum frequency generation with two pumps around this wavelength is observed with a conversion efficiency η = 1080%W-1cm-2. Difference frequency generation is also performed near degeneracy, with an external conversion efficiency η(ext) = 9.7%W-1cm-2 and a tunability of 570 nm. These results are promising for the feasibility of an integrated telecom source based on parametric fluorescence.

Injection-locking of terahertz quantum cascade lasers up to 35GHz using RF amplitude modulation.

We demonstrate that the cavity resonance frequency - the round-trip frequency - of Terahertz quantum cascade lasers can be injection-locked by direct modulation of the bias current using an RF source. Metal-metal and single-plasmon waveguide devices with roundtrip frequencies up to 35GHz have been studied, and show locking ranges above 200MHz. Inside this locking range the laser round-trip frequency is phase-locked, with a phase noise determined by the RF-synthesizer. We find a square-root dependence of the locking range with RF-power in agreement with classical injection-locking theory. These results are discussed in the context of mode-locking operation.