The zero-phonon transition rate of a nitrogen-vacancy center is enhanced by a factor of ~70 by coupling to a photonic crystal resonator fabricated in monocrystalline diamond using standard semiconductor fabrication techniques. Photon correlation meas
urements on the spectrally filtered zero-phonon line show antibunching, a signature that the collected photoluminescence is emitted primarily by a single nitrogen-vacancy center. The linewidth of the coupled nitrogen-vacancy center and the spectral diffusion are characterized using high-resolution photoluminescence and photoluminescence excitation spectroscopy.
We demonstrate coupling of the zero-phonon line of individual nitrogen-vacancy centers and the modes of microring resonators fabricated in single-crystal diamond. A zero-phonon line enhancement exceeding ten-fold is estimated from lifetime measuremen
ts at cryogenic temperatures. The devices are fabricated using standard semiconductor techniques and off-the-shelf materials, thus enabling integrated diamond photonics.
The generation of non-classical states of light via photon blockade with time-modulated input is analyzed. We show that improved single photon statistics can be obtained by adequately choosing the parameters of the driving laser pulses. An alternativ
e method, where the system is driven via a continuous wave laser and the frequency of the dipole is controlled (e.g. electrically) at very fast timescales is presented.
The resonance frequency of an InAs quantum dot strongly coupled to a GaAs photonic crystal cavity was electrically controlled via quantum confined Stark effect. Stark shifts up to 0.3meV were achieved using a lateral Schottky electrode that created a
local depletion region at the location of the quantum dot. We report switching of a probe laser coherently coupled to the cavity up to speeds as high as 150MHz, limited by the RC constant of the transmission line. The coupling rate and the magnitude of the Stark shift with electric field were investigated while coherently probing the system.
We demonstrate a method to locally control the temperature of photonic crystal devices via micron-scale electrical heaters. The method is used to control the resonant frequency of InAs quantum dots strongly coupled to GaAs photonic crystal resonators
. This technique enables independent control of large ensembles of photonic devices located on the same chip at tuning speed as high as hundreds of kHz.
Photonic crystal nanocavities at visible wavelengths are fabricated in a high refractive index (n>3.2) gallium phosphide membrane. The cavities are probed via a cross-polarized reflectivity measurement and show resonances at wavelengths as low as 645
nm at room temperature, with quality factors between 500 and 1700 for modes with volumes 0.7(lambda/n)^3. These structures could be employed for submicron scale optoelectronic devices in the visible, and for coupling to novel emitters with resonances in the visible such as nitrogen vacancy centers, and bio- and organic molecules.
We report the observation of nonclassical light generated via photon blockade in a photonic crystal cavity with a strongly coupled quantum dot. By tuning the frequency of the probe laser with respect to the cavity and quantum dot resonance we can pro
be the system in either photon blockade or photon-induced tunneling regime. The transition from one regime to the other is confirmed by the measurement of the second order correlation that changes from anti-bunching to bunching.
We demonstrate a method to locally change the refractive index in planar optical devices by photodarkening of a thin chalcogenide glass layer deposited on top of the device. The method is used to tune the resonance of GaAs-based photonic crystal cavi
ties by up to 3 nm at 940 nm, with only 5% deterioration in cavity quality factor. The method has broad applications for postproduction tuning of photonic devices.
