Quantum Hybrid Plasmonic Nanocircuits for Versatile Polarized Photon Generation

Abstract

However, single-photon sources relying on nonlinear processes suffer from probabilistic photon generation and an inherent tradeoff between efficiency and single-photon purity. To realize chip-scale photonic quantum technologies, such as photonic quantum computing, QPCs require deterministic single-photon generation. As such, deterministically positioned solid-state quantum emitters (QEs) (e.g., color centers in nanodiamonds, [6,7] quantum dots, [8,9] and defects in transition metal dichalcogenide monolayers [2,10] ) have been widely used as central blocks for high-quality single-photon sources. Different from free-space QEs that feature many shortcomings in ambient conditions, such as low quantum efficiencies, background emission, lifetime-limited photon rates, omnidirectional emission patterns, and linearly polarized transition dipole, the QEs coupled to dedicated photonic circuits hold the great potential for ideal on-demand solid-state sources that generate a pure stream of single photo ns at high repetition rates with welldefined polarizations and high efficiencies. The spontaneous emission of QEs can efficiently excite the fundamental and high-order modes in nanophotonic waveguides to directionally route the propagating single photons [11] or plasmons. [12] Thus, the radiative channel of emission into free space, in comparison, is small. [13] The single photons or plasmons that are well-confined and routed within the nanophotonic (photonic and plasmonic) waveguides are capable of being functionally modulated by integrating components of resonant cavities, photon detectors, beam splitters, phase shifters, spectral filters, free-space emitters, and mode converters, thereby enabling advanced functional QPCs. [14][15][16][17] Among nanophotonic waveguides, plasmonic waveguides enable extreme confinement of light into a subwavelength regime and allow strong light-matter interaction for efficiently coupling QE radiation. Recently, different types of plasmonic waveguide configurations such as metallic nanowires, wedge/ stripe waveguides, and V-grooves have been investigated for quantum nanophotonics. [7,12,18,19] However, metallic nanowires are originally synthesized from chemical reactions, which suffers from the difficulty of customized design for sophisticated circuits. Lithographically patterned plasmonic wedge/stripe

Multiple channelling single-photon emission with scattering holography designed metasurfaces

“…Following near-field approach, various plasmonic antennas have been utilized for engineering single-photon properties and have been used for generation of radially polarized 28 , circularly polarized 29 and vortex 27 beams, polarization encoded multichannel emission 30 , cavity-enhanced emission 31 and beam steering 32 . Many of these plasmonic antennas represent optical metasurfaces, i.e., dielectric ridge structures fabricated around QEs, that are utilized to scatter QE-excited SPPs into outgoing free-propagating waves, enabling thereby control over the QE emission into free space 27 – 29 .…”

Scattering holography designed metasurfaces for channeling single-photon emission

“…Various plasmonic antennas have been utilized for engineering the single photon properties and have been used for generation of radially-polarized [23], circularly polarized [24] and vortex [25] beams, polarization encoded multichannel emission [26], cavity-enhanced emission [27] and beam steering [28]. Many of these plasmonic antennas represent optical metasurfaces, i.e., dielectric ridge structures fabricated around QEs, that are utilized to scatter QEexcited SPPs into outgoing free-propagating waves, enabling thereby control over the QE emission into free space [23][24][25].…”

Facile integration of electro-optic SiO₂/ITO heterointerfaces in MIS structures for CMOS-compatible plasmonic waveguide modulation

“…Moreover, it has been theoretically predicted that the analysis of waveguides incorporating ITO as a semiconductor using a uniform accumulation layer (UAL) model is not rigorous, especially when the driving voltage necessary for tuning ITO is sufficiently high that uncertainty in determining the accumulation layer thickness is warranted [16][17][18][19][20][21][22][23][24] . This becomes clear when the epsilon-near-zero (ENZ) regime properties 25,26 are revealed, as shown using the rigorous graded-index layer (GIL) model analysis which shows that such cannot be predicted in those based on the UAL model.…”