Quantum optics with single molecules in a three-dimensional polymeric platform

Abstract

The successful development of future photonic quantum technologies heavily depends on the possibility of realizing robust, reliable and, crucially, scalable nanophotonic devices. In integrated networks, quantum emitters can be deployed as single-photon sources or non-linear optical elements, provided their transition linewidth is broadened only by spontaneous emission. However, conventional fabrication approaches are hardly scalable, typically detrimental for the emitter coherence properties and bear limitations in terms of geometries and materials. Here we introduce an alternative platform, based on molecules embedded in polymeric photonic structures. Three-dimensional patterns are achieved via direct laser writing around selected molecular emitters, which preserve near-Fourier-limited fluorescence. By using an integrated polymeric design, record-high photon fluxes from a single cold molecule are reported. The proposed technology allows to conceive a novel class of quantum devices, including integrated multi-photon interferometers, arrays of indistinguishable single photon sources and hybrid electro-optical nanophotonic devices.

Laser-Induced Frequency Tuning of Fourier-Limited Single-Molecule Emitters

“…Indeed, the effect is directly activated on the emitting sample with no need for additional fabrication and, being confined to the beam volit enables spatial resolution at the micron level. On the other side, once doped with single-molecule concentration, homogeneously deposited on the substrate via dropcasting and dessication [28], or even integrated in nanophotonic structures [15], DBT:Ac nanocrystals al- The demonstated results clearly show together several advantages of the proposed tuning approach: scalability, flexibility in the choice of substrate, high spectral and spatial resolution. We believe such characteristics will be crucial for the coupling of multiple emitters together in linear optical computing or simulation experiments and for the integration of molecules into resonant photonic structures.…”

“…Therefore, they can be operated as single-photon sources [6], combining high count rate and Fourier-limited linewidths [7][8][9], or as nano-probes with exquisite sensitivity to electric fields, pressure, and strain [10,11]. PAHbased quantum devices can also be readily integrated in photonic chips [12][13][14][15]. A major advantage of PAH systems resides in the possibility to mass-produce nominally identical fluorescent molecules at low costs, and still obtain outstanding optical and opto-electronic properties.…”

Objective-free excitation of quantum emitters with a laser-written micro parabolic mirror

“…Deterministic integration of micro optical components and individual quantum emitters can be achieved either by pre-or post-fabrication alignment, combined with lithographic fabrication. By lithographic techniques, various compact optical systems have been fabricated to control and manipulate light at the nanoscale, as for example waveguides [17,18], polarisation rotators [19], microdisc resonators [20], solid immersion lenses [21,22], objectives [23,24], parabolic antennas [25,26], dielectric pillar antennas [27], pillar microcavities [28].…”

Narrow Line Width Quantum Emitters in an Electron-Beam-Shaped Polymer

“…For instance, epitaxial InAs/GaAs quantum dots in GaAs nanowires 10−12 or strain-mediated quantum dots in single layers 13,14 of WSe 2 are recent examples of SPSs that can be deterministically positioned, but the observation of narrow optical resonances from such emitters remains challenging. Polymers offer an interesting platform for structuring the environment of SPSs at the nanoscale in order to couple them to photonic structures 15,17,16 on chip. While lithographic techniques have already shown impressive results for on-chip integration of nitrogen-vacancy centers 18 and quantum dots, 19 the outstanding properties of organic single molecules as quantum emitters and their compatibility with polymers motivate the quest for novel approaches based on electron-beam lithography to achieve nanophotonic integration while preserving their emission properties.…”