Fast optical modulation of the fluorescence from a single nitrogen–vacancy centre

Abstract

The much sought after optical transistor-the photonic counterpart of the electronic transistor-is poised to become a central ingredient in the development of optical signal processing. The motivation for using photons rather than electrons comes not only from their faster dynamics, but also from their lower crosstalk and robustness against environmental decoherence, which enable a high degree of integration and the realization of quantum operations . Here, we demonstrate that a single nitrogen-vacancy centre at room temperature can operate as an optical switch under non-resonant continuous-wave illumination. We show an optical modulation of more than 80% and a time response faster than 100 ns in the greenlaser-driven fluorescence signal, which we control through an independent near-infrared gating laser. Our study indicates that the near-infrared laser triggers a fast-decay channel of the nitrogen-vacancy mediated by promotion of the excited state to a dark band.Unlike charged particles such as electrons, photons interact extremely weakly with each other 3 . Therefore, an optical switch requires the mediation of a physical system to produce efficient photon-photon interactions. Different approaches to optical transistors have been proposed [4][5][6] , often based on nonlinearities in well-defined photonic resonators. More recently, a highfinesse optomechanical resonator has been used to demonstrate a transistor-like effect 7 . The ultimate goal for future optical commutation technologies is to rely on single atoms or molecules having the ability to manipulate light down to the single-photon level, which feature an intrinsically high nonlinearity and grant us access to exploiting the quantum nature of light 8 . In this direction, single-molecule optical processing has recently been achieved at low temperatures 2 . Furthermore, the inclusion of a third, dark state in the electronic structure of the atom or molecule has been argued to be particularly advantageous to reduce the effect of thermal decoherence 9,10 . The quest for operating such optical nano-transistors at room temperature is attracting considerable attention, as it would have a major impact on photonic technologies and enable high-speed signal processing in general.In parallel, research on single quantum emitters (either molecules or quantum dots) has focused on achieving stable and efficient light emission with well-defined properties [11][12][13][14] . However, a long-term stable source of single photons at room temperature still remains challenging with these emitters. In this context, nitrogen-vacancy centres in diamond have recently been intensely investigated owing to their emission stability. Nitrogen-vacancy centres are artificial atoms protected from their environment by 1 ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels, Barcelona, Spain, 2 ICREA-Institució Catalana de Recerca i Estudis Avançats, Barcelona 08010, Spain. † These authors contributed equally to this work. *e-mail: javier.garciadeabajo@icf...

Stable emission and fast optical modulation of quantum emitters in boron nitride nanotubes

“…(c) shows the optical modulation of NV centers in the nanodiamonds. In our system, we were able to achieve up to 60% modulation of a NV center fluorescence, which is comparable to the 80% modulation reported in [29]. The BNNTs, on the other hand, showed an optical modulation of 10% to 20%.…”

“…Fig.3. (a) shows the schematics for the optical modulation of BNNTs, similar to the scheme for the NV centers of nanodiamonds in [29]. With a CW 532 nm pump laser, the point defect in BN-NTs show stable fluorescence as shown in Fig.2.(i)-(j).…”

Near-infrared-assisted charge control and spin readout of the nitrogen-vacancy center in diamond

“…Our experiments uncover complex multiphoton absorption effects driven by visible and near-infrared excitation, resolving conflicting reports of both enhancement and quenching of NV − PL under simultaneous illumination with 532 nm visible and 1064 nm light [17][18][19][20] . We use this knowledge to demonstrate a new protocol for efficient spin-to-charge conversion via selective ionization of the NV − singlet that yields a 6-fold increase in the signal-to-noise ratio (SNR) for single-shot spin measurements and a pathway towards single-shot electron spin readout at room temperature.…”

“…Figure 2 presents measurements of the steady-state PL and corresponding charge distribution under coincident excitation with 532 nm and NIR light. Both sets of measurements exhibit non-monotonic variations as a func- tion of NIR power, P NIR , connecting conflicting observations of PL quenching and enhancement in different regimes 17,18,20 . The direct correlation between the relative changes in PL (Fig.…”

Local excitation of surface plasmon polaritons using nitrogen-vacancy centers

“…NV centers are of interest because they behave as artificial atoms and can be used as single photon sources [2]. Photostability is another important characteristic of NV centers [3].…”