Topological edge waves exist in the infinitely thin domain wall between two photonic crystals (PhCs) with opposite Berry phases. Compared to conventional waveguides that are prone to backscattering, edge waves under t...
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Topological edge waves exist in the infinitely thin domain wall between two photonic crystals (PhCs) with opposite Berry phases. Compared to conventional waveguides that are prone to backscattering, edge waves under topological protection show robustness against localized defects. However, the influence brought by the structural glide is not fully understood. In this work, we investigate the change of topological edge waves by gliding the PhCs. We study two groups of valley edge constructions as examples. The transmission bandwidth, wave velocity, intrinsic losses and robustness are functions of the glide parameter. We fabricated samples and conducted experiments in the microwave regime, and measured results that matched well with the full-wave simulations. Our research indicates that glide-symmetric dislocation is an essential degree of freedom to manipulate topological edge waves.
Fluorescent plastically bendable crystals are a promising alternative to silicon-based materials for fabricating photonic integrated circuits, owing to their optical attributes and mechanical compliance. Mechanically ...
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Fluorescent plastically bendable crystals are a promising alternative to silicon-based materials for fabricating photonic integrated circuits, owing to their optical attributes and mechanical compliance. Mechanically bendable plastic organic crystals are rare. Their formation requires anisotropic intermolecular interactions and slip planes in the crystal lattice. This work presents three fluorescent plastically bendable crystalline materials namely, 2-((E)-(6-methylpyridin-2-ylimino)methyl)-4-chlorophenol (SB1), 2-((E)-(6-methylpyridin-2-ylimino)methyl)-4-bromophenol (SB2), and 2-((E)-(6-Bromopyridin-2-ylimino)methyl)-4-bromophenol (SB3) molecules. The crystal plasticity in response to mechanical stress facilitates the fabrication of various monolithic and hybrid (with a tip-to-tip coupling) photonic circuits using mechanical micromanipulation with an atomic force microscope cantilever tip. These plastically bendable crystals act as active (self-guiding of fluorescence) and passive waveguides both in straight and extremely bent (U-, J-, and O-shaped) geometries. These microcircuits use active and passive waveguiding principles and reabsorbance and energy-transfer mechanisms for their operation, allowing input-selective and direction-specific signal transduction.
Subtractive photonics is presented as a method for implementing photonic waveguides into any bulk CMOS or electronics process. Metal and glass are patterned in the backend layers by the foundry to reveal suspended die...
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Subtractive photonics is presented as a method for implementing photonic waveguides into any bulk CMOS or electronics process. Metal and glass are patterned in the backend layers by the foundry to reveal suspended dielectric waveguides when the metal is etched away. This method requires a simple wet etch and provides waveguiding of light up to the visible regime using the broad transparency windows of silicon oxides. Mechanical, chemical, and photonic considerations are discussed, and photonic design is extensively detailed in the context of a 180-nm CMOS process. Example waveguides are constructed and measured, with losses as low as 4.1 dB/cm for a multimode waveguide at 1550 nm. In addition, waveguides are measured in the visible range, waveguide-photodiode couplers are detailed, and electronic-photonic systems are demonstrated to be unaffected by the etching.
Sound energy control at low frequencies ( = 1000 Hz) is necessary and very important in acoustics, especially when considering scientific and technological aspects. In this work, a modular acoustic metamaterial compos...
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Sound energy control at low frequencies ( = 1000 Hz) is necessary and very important in acoustics, especially when considering scientific and technological aspects. In this work, a modular acoustic metamaterial composed of a main waveguide loaded with small quarter-wavelength tubes is presented. Theoretical, numerical, and experimental methods are used to describe the accumulation of sound absorption peaks below the structure's bandgap with the number of peaks proportional to the structure's periodicity. The origin of the bandgap is due to the loaded tubes in the main waveguide. Ultra-low phase velocity ( c (p) = 16 m/s) and critical coupling were obtained in the model, which allowed perfect sound absorption at 292 Hz with a structure reaching a ratio of ? / 90. The experimental results in the impedance tube support the theoretical and numerical discussions and demonstrate a sound energy control of 89% and 84% at 686 and 422 Hz, respectively. Finally, this work contributes to advances in the field of control and manipulation of low-frequency sound energy through periodic structures.
Scalable quantum photonic technologies require the low-lossintegrationof many identical single-photon sources with photonic circuitry ona chip. Relatively complex quantum photonic circuits have alreadybeen demonstrate...
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Scalable quantum photonic technologies require the low-lossintegrationof many identical single-photon sources with photonic circuitry ona chip. Relatively complex quantum photonic circuits have alreadybeen demonstrated;however, sources used so far relied on parametricdown-conversion which has a probabilistic nature that intrinsicallylimits its efficiency and scalability. Quantum emitter-based single-photonsources are free of this limitation, but frequency matching of multipleemitters within a single circuit remains challenging. In this work,we demonstrate a key component in this regard in the form of a fullymonolithic GaAs circuit combining two frequency-matched quantum dotsingle-photon sources interconnected with a low-loss on-chip beamsplitterconnected via single-mode ridge waveguides. This device enabled usto perform a two-photon interference experiment on-chip with a visibilityreaching 66%. Our device could be further scaled up, providing a clearpath to increasing the complexity of quantum circuits toward fullyscalable integrated quantum technologies.
Nanoscale Fano resonances, with applications from telecommunications to ultrasensitive biosensing, have prompted extensive research. We demonstrate that a superconducting qubit, jointly coupled to microwave waveguides...
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Nanoscale Fano resonances, with applications from telecommunications to ultrasensitive biosensing, have prompted extensive research. We demonstrate that a superconducting qubit, jointly coupled to microwave waveguides and an inter-digital transducer composite device, can exhibit acoustic Fano resonances. Our analytical framework, leveraging the Taylor series approximation, elucidates the origins of these quantum acoustic resonances with periodic Fano-like interference. By analyzing the analytical Fano parameter, we demonstrate that the Fano resonances and their corresponding Fano widths near the resonance frequency of a giant atom can be precisely controlled and manipulated by adjusting the time delay. Moreover, not just the near-resonant Fano profiles, but the entire periodic Fano resonance features can be precisely modulated from Lorentz, Fano to quasi-Lorentz shapes by tuning the coupling strength of the microwave waveguide. Our analytical framework offers insights into the control and manipulation of periodic Fano resonances in quantum acoustic waves, thereby presenting significant potential for applications such as quantum information processing, sensing, and communication. (c) 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement
Aluminum nitride (AlN)-based optoelectronics have demonstrated great promises in application scenarios such as waveguides, beam splitters, directional couplers and interferometers. Yet, existing studies primarily focu...
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Aluminum nitride (AlN)-based optoelectronics have demonstrated great promises in application scenarios such as waveguides, beam splitters, directional couplers and interferometers. Yet, existing studies primarily focus on its photonic applications in the UV-Vis spectrum, with limited exploration in the mid and long IR spectrum. With its strong polarity, AlN can host the surface phonon polaritons (SPhPs) and modulate radiative properties via inducing localized resonances in metasurface. Herein, we fully investigate propagating and localized SPhPs and infrared radiative properties of AlN nanoresonators by combining spectroscopic ellipsometry measurements and multiscale simulations, and further explore their dependence on temperature and structural morphology. Elevated temperatures enhance anharmonic phonon scattering of AlN, thus weakening their ability to support SPhPs. The absorption spectra of anisotropic AlN nanoresonators are dominated by two peaks, with the height playing a key role in tuning them due to the effect on the polaritonic field disturbance. This work provides physical insights into temperature-induced spectral tuning of AlN nanoresonators and facilitates the development of photonics applications under high-temperature conditions.
Tunable interaction strength between a side-coupled ring resonator and an acoustic waveguide structure is demonstrated. Fano resonances in the weak coupling regime are observed from the interference between a discrete...
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Tunable interaction strength between a side-coupled ring resonator and an acoustic waveguide structure is demonstrated. Fano resonances in the weak coupling regime are observed from the interference between a discrete state of the ring resonator and a continuum state of the waveguide. As the distance between the two structures is decreased, a transition from weak to strong coupling regime is obtained, where we observe splitting in the transmission spectrum and Rabi oscillations in the temporal behavior for smaller values. The findings of the finite-element method simulations are supported with the results obtained from a simple theoretical model in which one can explain the dynamics of the hybrid modes. The results can contribute to device applications in acoustic sensors, switches, and surface acoustic wave integrated circuits.
Vector inversion generators or spiral generators are compact, high voltage pulse generators consisting of a pair of conducting foils wound in a spiral and a switch. We developed an improved analytical model predicting...
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Vector inversion generators or spiral generators are compact, high voltage pulse generators consisting of a pair of conducting foils wound in a spiral and a switch. We developed an improved analytical model predicting the time evolution of the output voltage of such spiral generators. Our model (i) takes into account that the current in the switch results from the current on active and passive waveguides and (ii) takes into account the losses of the conductor in equations describing the propagation of voltage and current pulses in both waveguides. The model is compared to experimental results involving different input switches and at different temperatures to investigate the influence of resistive losses on the output voltage. The model is further developed to obtain the time evolution of the current in the switch. Our model is then used to predict the amplitude of the first two peaks of the oscillatory response of spiral generators as a function of a set of dimensionless parameters.
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