Ariel Levenson

Indistinguishable single photons from a single-quantum dot in a two-dimensional photonic crystal cavity

We report on the spontaneous emission of a single-quantum dot embedded in a two-dimensional photonic crystal cavity. The resonant coupling between the dot and the strongly localized optical mode significantly shortens the spontaneous emission lifetime, so that the coherence time of the emitted photons is dominated by radiative effects: The emitted photons are indistinguishable, with a mean wave-packet overlap as high as 72%.

Ultrafast dynamics of the third-order nonlinear response in a two-dimensional InP-based photonic crystal

We report experimental demonstration of very fast nonlinear response around 1.5μm in an InP-based two-dimensional photonic crystal. The nonlinearity produced by low pump powers via carrier induced nonlinear refractive index, leads to an efficient wavelength shift of a photonic crystal resonance observed in reflectivity. Thus we show that it is possible to obtain round the clock (rise and recovery) switching times shorter than 10ps with contrast ratio higher than 80%.

All-optical bistable band-edge Bloch modes in a two-dimensional photonic crystal

We demonstrate experimentally all-optical bistable operation in an InP-based two-dimensional photonic crystal slab lying on top of a Bragg reflector. Bistability is obtained around 1550nm, using a low group velocity mode at the band edge of the photonic dispersion characteristic. The origin of the bistable regime is shown to be the fast (275ps relaxation time), electronically induced nonlinear refraction index. A low intensity threshold of 4kW∕cm2 was observed, with a contrast of 65% between the high and low reflectivity states.

Spontaneous mirror-symmetry breaking in coupled photonic-crystal nanolasers

The observation of symmetry breaking in a coupled nanolaser system could yield new types of switchable devices.

Continuous-wave operation of photonic band-edge laser near 1.55 μm on silicon wafer

We report on the continuous-wave operation of a band edge laser at room temperature near 1.55 μm in an InGaAs/InP photonic crystal. A flat dispersion band-edge photonic mode is used for surface normal operation. The photonic crystal slab is integrated onto a Silicon chip by means of Au/In bonding technology, which combines two advantages, efficient heat sinking and broad band reflectivity.

Tuning a two-dimensional photonic crystal resonance via optical carrier injection

We report on wide wavelength tuning through optical injection of carriers of a photonic resonance observed in reflectivity at 1543 nm in an InP-based two-dimensional photonic crystal slab. An 8-nm blueshift, which represents 20 times the resonance linewidth, is observed when a 4-kW/cm2 intense optical pump is incident on the sample. An analytical model that we developed, based on a coupled-mode nonlinear approach, allows us to describe this phenomenon in detail.

χ (2) semiconductor photonic crystals

Playing a central role in microelectronics and optoelectronics, semiconductors almost stand apart from applications involving second-order nonlinear effects such as frequency converters, tunable sources, parametric amplifiers, and switches. The reasons are twofold: their strong chromatic dispersion, which prevents the interacting waves from propagating with the same phase velocity (phase mismatch), and the shortness of the semiconductor devices, which adds more difficulty to achieving reasonable nonlinear efficiencies. By exploiting the unique properties of photonic crystals, we demonstrate simultaneous phase matching and enhancement of the fields under nonlinear interaction. We demonstrate a second-harmonic efficiency growth faster than the fifth power of the structure length.

Optical amplification in two-dimensional photonic crystals

Optical amplification is demonstrated in a two-dimensional photonic crystal. Amplification at 1575nm is observed in the direction normal to the plane of periodicity, by pumping the device at 810nm. A gain up to 27dB is measured with moderate pump fluence (50μJ∕cm2). Gain is shown to clamp as laser threshold is attained.

Doubly resonant photonic crystal for efficient laser operation: Pumping and lasing at low group velocity photonic modes

An InP-based two-dimensional photonic crystal slab laser is optimized in order to exhibit low group velocity modes both at the pumping and the lasing wavelength. Laser operation is demonstrated at 1566nm in the pulsed regime. A threshold of 4kW∕cm2 is demonstrated by pumping at the photonic mode lying in the bound quantum well electronic levels, one longitudinal optical phonon energy below the lasing photonic mode.

Choose Your Color from the Photonic Band Edge Nonlinear Frequency Conversion

Ordinary Bragg reflectors, also known as one-dimensional photonic band gap structures (PBGs), display extraordinary linear and nonlinear optical properties that present a remarkable opportunity: the simultaneous availability of exact phase matching conditions and field confinement that act together to yield significantly enhanced second and third harmonic generation, frequency downconversion, and multi-wave mixing processes. This opens the door to a new class of micrometer-sized devices that represent a new generation of efficient parametric sources for up- and down-conversion processes.