32 citations · 113 across the 14 of their papers we have counts for
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Quantum Theory of Third-harmonic Generation in Epsilon-Near-Zero Materials
Sonia Alipour, Riccardo Franchi, Tornike Shubitidze +3
We present a theoretical framework, based on the Green's tensor quantization method, to describe third-harmonic generation in epsilon-near-zero (ENZ) materials and derive analytica…
Mid-Infrared Single-Photon Detection via Enhanced Cross-Phase Modulation in Topology-Optimized Epsilon-Near-Zero Dual-Wavelength Nanocavities
Luca Dal Negro, Riccardo Franchi, Marco Ornigotti
We use the Green's tensor quantization theory for open resonant nanostructures with absorption losses to study cross-phase modulation (XPM) at the single-photon level in nanoscale…
Structural and physical properties of gyromorphs and disordered stealthy hyperuniform media
Murray Skolnick, Riccardo Franchi, Luca Dal Negro +2
Disordered stealthy hyperuniform materials combine liquid-like statistical isotropy with crystal-like homogeneity, suppressed density fluctuations at large length scales, bounded h…
On-Chip Interferometric Excitation of an Infinity-Loop Microresonator
Davide Olivieri, Bülent Aslan, Stefano Biasi +2
Integrated photonics is a powerful platform for exploring Hermitian and non-Hermitian physics. Beyond device geometry, controlling how resonators are driven is crucial to access an…
Nonlinear Quantum Electrodynamics of Epsilon-Near-Zero Nanocavities
Luca Dal Negro, Riccardo Franchi, Marco Ornigotti
We investigate single-photon nonlinear refractive index change and frequency shift of Epsilon-Near-Zero (ENZ) sub-wavelength nanocavities. We apply the rigorous quantum Langevin-no…
The Taiji microresonator as an unidirectional spiking neuron
Stefano Biasi, Alessandro Foradori, Riccardo Franchi +3
While biological neurons ensure unidirectional signalling, scalable integrated photonic neurons, such as silicon microresonators, respond the same way regardless of excitation dire…
The infinity-loop microresonator: A new integrated photonic structure working on an exceptional surface
Riccardo Franchi, Stefano Biasi, Diego Piciocchi +1
Exceptional points, where eigenvalues and eigenvectors coalesce, impact the behavior of different photonics components that show, e.g., enhanced sensing, coherent perfect absorptio…
Interferometric cavity ring-down technique for ultra-high Q-factor microresonators
Stefano Biasi, Riccardo Franchi, Lorenzo Pavesi
Microresonators (MRs) are key components in integrated optics. As a result, the estimation of their energy storage capacity as measured by the quality factor (Q) is crucial. Howeve…
An interferometric method to estimate the eigenvalues of a Non-Hermitian two-level optical system
Stefano Biasi, Riccardo Franchi, Filippo Mione +1
Non-Hermitian physics has found a fertile ground in optics. Recently, the study of mode degeneracies, i.e. exceptional points, has led to the discovery of intriguing and counterint…
Influence of the bus waveguide on the linear and nonlinear response of a taiji microresonator
Riccardo Franchi, Stefano Biasi, Alberto Muñoz de las Heras +3
We study the linear and nonlinear response of a unidirectional reflector where a nonlinear breaking of the Lorentz reciprocity is observed. The device under test consists of a race…
Nonlinearity-induced reciprocity breaking in a single non-magnetic Taiji resonator
A. Muñoz de las Heras, R. Franchi, S. Biasi +3
We report on the demonstration of an effective, nonlinearity-induced non-reciprocal behavior in a single non-magnetic multi-mode Taiji resonator. Non-reciprocity is achieved by a c…