Final Report Summary - PLASMOLIGHT (NEW FRONTIERS IN PLASMON OPTICS: FROM NANOCHEMISTRY TO QUANTUM OPTICS)
At this point in time where plasmon optics has become a mature field of research, the PLASMOLIGHT project aimed at creating new bridges with other scientific disciplines that can greatly benefit from both the optical and thermal properties of metallic nanostructures. In particular, we focused on two independent subprojects, in which plasmonics is combined with Chemistry and Quantum optics, respectively.
In the first subproject, we investigate how plasmonics can contribute to control molecular immobilization and patterning on the nanometer scale. To this aim, we have successfully developed two different strategies. We first demonstrated the capability of plasmonic nanostructures to pattern photosensitive polymers with a 10nm resolution [Volpe et al, NanoLetters 12, 4864-4868 (2012)]. In a second approach we proposed a novel approach in which the enhanced local field in the hot spot is the driving mechanism that triggers the binding of proteins via three-photon absorption. This way, we demonstrated exclusive immobilization of nanoscale amounts of proteins into the nanometer-sized gap of plasmonic dimers. The immobilized proteins can then act as a scaffold to subsequently attach any additional nanoscale object such as a molecule or a nanocrystal [Galloway et al, NanoLetters 13, 4299 (2013)]. These approaches address some of the major limitations of existing methods by combining parallel patterning over large areas with high spatial resolution. In particular, we foresee they could highly benefit to the field of biosensing and optical spectroscopy [Ortega et al, Nano Lett. 14, 2636–2641 (2014)].
The second part of the project studied the use of the latest advances in nano-optics and especially plasmonics to develop novel integrated quantum functionalities based on NV centers in diamond. The first main achievement of this subproject was the development of a new method to pick-up and 3D manipulate in solution individual nanodiamonds hosting a single NV center. Remarkably the axis of the trapped spin remains fixed over time and can be controlled by rotating the polarization of the trapping laser. We demonstrated this level of control offers a powerful way to probe the electric and magnetic environment on the nanometer scale [Geiselmann et al, Nature Nanotechnol. 8, 175-179 (2013)]. It is also an efficient way to locate individual NV at predefined positions of an optical nanoantenna [Geiselmann et al, Nano Lett. 14, 1520-1525 (2014)]. A second main achievement of the project was to combine surface chemistry with nanomanipulation to deterministically couple a single NV to a channel plasmon mode in a V-groove plasmonic waveguide [Bermudez et al, Nature Commun. 6, 7883 (2015)]. This hybrid architecture features unique performance over the state-of-the-art and is foreseen to contribute to the elaboration of future integrated quantum optics functionalities. Another main achievement is the experimental demonstration and full characterization of fast all-optical switching in a single NV center [Geiselmann et al, Nature Phys. 9, 785-789 (2013)]. We showed that a single nitrogen–vacancy centre at room temperature can operate as an optical switch under non-resonant continuous-wave illumination. We showed an optical modulation of more than 80% and a time response faster than 100ns in the green- laser-driven fluorescence signal, which we control through an independent near-infrared gating laser.
Beyond its multiple scientific achievements, the PLASMOLIGHT project also led to two ERC-Proof-of-Concept projects (PELO and SMARTLENS).
In the first subproject, we investigate how plasmonics can contribute to control molecular immobilization and patterning on the nanometer scale. To this aim, we have successfully developed two different strategies. We first demonstrated the capability of plasmonic nanostructures to pattern photosensitive polymers with a 10nm resolution [Volpe et al, NanoLetters 12, 4864-4868 (2012)]. In a second approach we proposed a novel approach in which the enhanced local field in the hot spot is the driving mechanism that triggers the binding of proteins via three-photon absorption. This way, we demonstrated exclusive immobilization of nanoscale amounts of proteins into the nanometer-sized gap of plasmonic dimers. The immobilized proteins can then act as a scaffold to subsequently attach any additional nanoscale object such as a molecule or a nanocrystal [Galloway et al, NanoLetters 13, 4299 (2013)]. These approaches address some of the major limitations of existing methods by combining parallel patterning over large areas with high spatial resolution. In particular, we foresee they could highly benefit to the field of biosensing and optical spectroscopy [Ortega et al, Nano Lett. 14, 2636–2641 (2014)].
The second part of the project studied the use of the latest advances in nano-optics and especially plasmonics to develop novel integrated quantum functionalities based on NV centers in diamond. The first main achievement of this subproject was the development of a new method to pick-up and 3D manipulate in solution individual nanodiamonds hosting a single NV center. Remarkably the axis of the trapped spin remains fixed over time and can be controlled by rotating the polarization of the trapping laser. We demonstrated this level of control offers a powerful way to probe the electric and magnetic environment on the nanometer scale [Geiselmann et al, Nature Nanotechnol. 8, 175-179 (2013)]. It is also an efficient way to locate individual NV at predefined positions of an optical nanoantenna [Geiselmann et al, Nano Lett. 14, 1520-1525 (2014)]. A second main achievement of the project was to combine surface chemistry with nanomanipulation to deterministically couple a single NV to a channel plasmon mode in a V-groove plasmonic waveguide [Bermudez et al, Nature Commun. 6, 7883 (2015)]. This hybrid architecture features unique performance over the state-of-the-art and is foreseen to contribute to the elaboration of future integrated quantum optics functionalities. Another main achievement is the experimental demonstration and full characterization of fast all-optical switching in a single NV center [Geiselmann et al, Nature Phys. 9, 785-789 (2013)]. We showed that a single nitrogen–vacancy centre at room temperature can operate as an optical switch under non-resonant continuous-wave illumination. We showed an optical modulation of more than 80% and a time response faster than 100ns in the green- laser-driven fluorescence signal, which we control through an independent near-infrared gating laser.
Beyond its multiple scientific achievements, the PLASMOLIGHT project also led to two ERC-Proof-of-Concept projects (PELO and SMARTLENS).