Dynamic modulation of photonic crystal nanocavities using gigahertz acoustic phonons

Abstract

Photonic crystal membranes (PCM) provide a versatile planar platform for on-chip implementations of photonic quantum circuits 1-3 . One prominent quantum element is a coupled system consisting of a nanocavity and a single quantum dot (QD) 4-7 which forms a fundamental building block for elaborate quantum information networks 8-10 and a cavity quantum electrodynamic (cQED) system controlled by single photons 3 . So far no fast tuning mechanism is available to achieve control within the system coherence time. Here we demonstrate dynamic tuning by monochromatic coherent acoustic phonons formed by a surface acoustic wave (SAW) with frequencies exceeding 1.7 gigahertz, one order of magnitude faster than alternative approaches 5-7 . We resolve a periodic modulation of the optical mode exceeding eight times its linewidth, preserving both the spatial mode profile and a high quality factor. Since PCMs confine photonic and phononic excitations 11,12 , coupling optical to acoustic frequencies, our technique opens ways towards coherent acoustic control of optomechanical crystals.In basic research SAWs found applications in the investigation of fundamental quantum effects in nanosystems 13-17 , the manipulation of photonic bandgap structures 18 , microcavity and surface plasmon polaritons 19-21 with frequencies spanning from a few megahertz up to a several gigahertz. We electrically generate SAWs by applying a short radio frequency (RF) voltage pulse to interdigital transducer electrodes (IDT) as shown schematically in Fig. 1 (a). As this pulse propagates across the PCM, it dynamically

Optomechanic interactions in phoxonic cavities

“…Let us notice that several cavity optomechanic structures have been studied recently, both theoretically and experimentally, however without necessarily referring to the simultaneous confinement of phonons and photons. The acousto-optic interactions have been considered in photonic cavities inside nanobeam [12][13][14] and slab [15][16][17][18] structures, as well as in waveguides (nanobeams, 19,20 photonic fiber 21 and 2D crystal waveguides 22 ). A review of the modeling of light-sound interaction in nanoscale cavities and waveguides is given in Ref.…”

Ultrafast non-local control of spontaneous emission

“…The ideal control method for semiconductor nanocavities would allow the ultrafast manipulation of the coupling rate g and/or of the cavity-loss rate κ, without directly affecting the population and the phase of the emitter. Although various methods for the control of semiconductor CQED systems have been demonstrated, for example by tuning the emitter or cavity frequency using electric field 7 , strain 8 or nanomechanical deformation 9,10 , none of these has been shown to provide the control of radiative processes on the required subnanosecond timescales. The fast wavelengthdetuning techniques theoretically proposed in Johnson et al 11 and Thyrrestrup et al 12 are extremely challenging to implement without directly perturbing the emitter's evolution, and are intrinsically associated with a wavelength chirp.…”

Vector network analyzer measurement of the amplitude of an electrically excited surface acoustic wave and validation by X-ray diffraction

“…For small amplitudes, fluid mixing is favored; for intermediate amplitudes the droplet is translated, and for higher amplitudes one can observe fluid jetting and atomization. Other systems that call for quantitative SAW analyses are quantum systems such as quantum dots, [32][33][34][35] photonic cavities, [36][37][38] single carrier transport systems, [39][40][41] and SAW driven single electron transport (SAW/SET) in two dimensional electron gas (2DEG) heterostructures 42,43 like GaAs/Al x Ga 1Àx As. In 2DEG heterostructures, the SAWs can induce a quantized current I ¼ nef, where n is an integer, e is the elementary electron charge and f is the frequency of the SAWs.…”