Periodic Reporting for period 1 - PhotonMeta (Advanced Single-Photon Sources Based on On-Chip Hybrid Plasmon-Emitter Coupled Metasurfaces)
Période du rapport: 2022-06-01 au 2024-05-31
Single-photon sources are crucial for many quantum information technologies, including quantum communications, computation, sensing and metrology. Typical stand-alone quantum emitters (QEs), such as quantum dots and defects in diamonds, feature low emission rates, nondirectional emissions, and poorly defined polarization properties, which prevents QEs from being directly used as single-photon sources in practical applications. Various micro/nano structures have been developed in recent years to enhance QE emission rates by making use of the Purcell effect via engineering their immediate dielectric environment, but the control of polarization, direction, and wavefront of the emitted photons has still been rarely addressed. The main objective of the project is to develop a general design approach for high-performance single-photon sources and demonstrate its use by designing and fabricating a series of advanced single-photon nanodevices with different functionalities. First, the underlying physics of QE coupling to surface nanostructures will be thoroughly investigated. We will then develop a novel holography implementation, vectorial scattering (computer-generated) holography, generating directly profiles of hybrid plasmon-QE coupled metasurfaces. Finally, based on the developed design approach, a series of nanodevices will be demonstrated, on-chip realizing photon emission with desirable polarization and phase profiles, including those of vector vortex beams. This project will enable the realization of single-photon sources with radiation channels that have distinct directional and polarization characteristics, extending thereby possibilities for designing complex photonic systems for quantum information processing. Furthermore, this project will facilitate knowledge exchange via dissemination activities along with researcher training in transferable skills, being fully committed to open science principles and chronicling the whole project in an open online logbook.
In this project, we have proposed a new avenue by introducing metasurfaces to on-chip couple with QEs, which can efficiently outcouple the QEs-excited nonradiative surface plasmon polaritons to photon emission encoded with specific spin and orbital angular momenta (SAM and OAM), respectively. We have realized independent manipulation of the single-photon SAM and OAM states by using metasurface dimers of orthogonal nanobricks that generate (by scattering) high purity SAM (98% for S3 > 0.9). By arranging the nanobrick dimers along different metasurface trajectories controlling OAM, high-purity SAM states are superimposed with OAM states corresponding to different phase-front helicities, for example, l = 0, 1, and 2. Furthermore, we have demonstrated the generation of high-purity linearly polarized (LP) single-photon vortex beams. Remarkably, the design strategy enables simultaneous generation of high-purity orthogonal LP single-photon beams with arbitrary different OAMs, meeting thereby growing demands for increasing the quantum information channel capacity. Thus, by selectively covering azimuthally different metasurface areas with differently arranged nanobricks, we realize multiplexing of single-photon emission channels with orthogonal LPs carrying different topological charges (OAMs) and confirm their entanglement.
Moreover, we have developed the vectorial scattering holography approach, as an inverse design method, with both single-channel and multiple-channel regimes for flexibly designing versatile on-chip QE-coupled metasurfaces. Based on the proposed approach, we design, fabricate, and characterize on-chip quantum light sources of two well-collimated single-photon beams propagating along different off-normal directions with orthogonal linear polarizations. Furthermore, we experimentally demonstrate on-chip generation of multichannel quantum emission encoded with different SAMs and OAMs in each channel. The multichannel holography approach is further extended for tempering the strength of QE emission into a particular channel. The holography-based inverse design approach developed and demonstrated on-chip quantum light sources with multiple degrees of freedoms enable thereby a powerful platform for quantum nanophotonics, especially relevant for advanced quantum photonic applications, e.g. high-dimensional quantum information processing.
In summary, with above achievements, we have published 7 peer-reviewed papers in high-impact journals (all of them are JCR Q1), including Science Advances (selected as cover), Nature Communications, Advanced Materials, and ACS Nano. I have also attended four international conferences and given oral talks, including two invited talks.
Moreover, we have developed the vectorial scattering holography approach, as an inverse design method, with both single-channel and multiple-channel regimes for flexibly designing versatile on-chip QE-coupled metasurfaces. Based on the proposed approach, we design, fabricate, and characterize on-chip quantum light sources of two well-collimated single-photon beams propagating along different off-normal directions with orthogonal linear polarizations. Furthermore, we experimentally demonstrate on-chip generation of multichannel quantum emission encoded with different SAMs and OAMs in each channel. The multichannel holography approach is further extended for tempering the strength of QE emission into a particular channel. The holography-based inverse design approach developed and demonstrated on-chip quantum light sources with multiple degrees of freedoms enable thereby a powerful platform for quantum nanophotonics, especially relevant for advanced quantum photonic applications, e.g. high-dimensional quantum information processing.
In summary, with above achievements, we have published 7 peer-reviewed papers in high-impact journals (all of them are JCR Q1), including Science Advances (selected as cover), Nature Communications, Advanced Materials, and ACS Nano. I have also attended four international conferences and given oral talks, including two invited talks.
Generally, there are two different routes for manipulating photon emission from QEs, viz. far- and near-field approaches. In the far-field configurations, the photon emission is manipulated using bulky optical components, like lenses, mirrors, and polarizers, which unavoidably increase the system complexity and lower the efficiency of photon emission. In recent years, metalenses have been introduced to manipulate nonclassical light in a manner of their bulky counterparts, i.e. operating as external components that influence the radiation focusing, direction, and polarization after the quantum emission was generated. In our project, we utilize the near-field configurations, where QEs are nonradiatively coupled to metasurfaces, which can generate polarized and directional photon emission directly by shaping the out-of-plane scattering of surface (nonradiative) modes. This approach is apparently more efficient and compact by virtue of dispensing with the external components.
The developed inverse design approach provides a powerful tool to design versatile on-chip emitter-coupled holography metasurfaces to flexibly structure multichannel photon emission with more freedom, including arbitrary directions, polarizations, and intensity ratios. The on-chip room-temperature versatile handling of photon states opens thereby exciting perspectives for designing advanced single-photon sources and would contribute to further developments within chiral quantum optics, concerned with advanced functionalities. With this toolbox at hand, one is well equipped to generate very complex structured single-photon beams in multiple channels, which hold the promise for future development of quantum channel division/multiplexing circuits for high-density data and multidimensional information processing.
The developed inverse design approach provides a powerful tool to design versatile on-chip emitter-coupled holography metasurfaces to flexibly structure multichannel photon emission with more freedom, including arbitrary directions, polarizations, and intensity ratios. The on-chip room-temperature versatile handling of photon states opens thereby exciting perspectives for designing advanced single-photon sources and would contribute to further developments within chiral quantum optics, concerned with advanced functionalities. With this toolbox at hand, one is well equipped to generate very complex structured single-photon beams in multiple channels, which hold the promise for future development of quantum channel division/multiplexing circuits for high-density data and multidimensional information processing.