C.E. Png

• Institute of High Performance Computing

We study high-quality factor (high Q ) resonances in periodic and disordered arrays of Mie resonators from the perspectives of both Bloch wave theory and multiple scattering theory. We reveal that, unlike a common belief, the bound states in the continuum (BICs) derived by the Bloch-wave theory do not directly determine the resonance with the highe...

We explore the generation and optimization of entanglement between atoms chirally coupled to finite one-dimensional spin chains, functioning as spin cavities. By diagonalizing the spin cavity Hamiltonian, we identify a parity effect that influences entanglement, with small even-sized cavities chirally coupled to atoms expediting entanglement genera...

This work investigates the effects of time-varying media, where optical properties change over time, on electromagnetic wave propagation, focusing on plane waves and free-electron evanescent waves. We introduce a switching parameter, $\tau$, to model ultrafast switching in the femtosecond to nanosecond range. For plane-wave incidence at angular fre...

In this study, we construct Fabry-Perot cavities in which nanostructured, thin resonant metasurfaces act as mirrors. We develop a temporal coupled-mode theory and provide an accurate description of the resonances supported by these cavities, deriving analytically their transmission characteristics. The presence of metasurface mirrors introduces a s...

In this article, we demonstrate dense resonant peaks in the transmission spectra of a rectangular waveguide inscribed with a stretched moiré pattern. We investigated an array of silicon waveguides with sinusoidally modulated cladding of varying depth of modulation. The investigation reveals a critical depth of modulation that splits the geometries...

We study high quality-factor (high Q) resonances supported by periodic arrays of Mie resonators from the perspectives of both Bloch wave theory and multiple scattering theory. We reveal that, unlike a common belief, the bound states in the continuum (BICs) derived by the Bloch-wave theory do not directly determine the resonance with the highest Q v...

To keep pace with the expanding data capacity in modern communications and increasing on‐chip integration density, it is highly desirable to have electro‐optic modulators featured with compact footprint, large modulation bandwidth, low energy consumption, and full complementary metal‐oxide‐semiconductor (CMOS) compatibility. Here, this work experim...

The recent emerging alternative to classic numerical Fast Fourier transform (FFT) computation, based on GHz ultrasonic waves generated from and detected by piezoelectric transducers for wavefront computing (WFC), is more efficient and energy-saving. In this paper, we present comprehensive studies on the modeling and simulation methods for ultrasoni...

A Fabry-Perot resonator utilizes two solid, non-resonating, reflecting mirrors to form resonant patterns when the separation between the mirrors satisfies the resonance conditions. The resonant mode concentrates at the middle of the cavity. In this study, we constructed a Fabry-Perot cavity with nanostructured resonant metasurfaces as meta-mirrors....

In this article, we demonstrate dense resonant peaks in the transmission spectra of a rectangular waveguide inscribed with a stretched moir\'e pattern. We investigated an array of silicon waveguides with sinusoidally modulated cladding of varying depth of modulation. The investigation reveals a critical depth of modulation that splits the geometrie...

Terahertz (THz) radiation has broad applications ranging from medical imaging to spectroscopy. One viable source of high‐intensity THz radiation is the Smith–Purcell (SP) effect, which involves charge carriers moving over a periodic surface. Conventional SP emitters use electron beams to generate charge carriers, necessitating bulky electron accele...

In this article, using principles of automatic differentiation, we demonstrate a generic deep learning representation of group refractive index for photonic channel waveguides. It enables evaluation of group refractive indices in a split of second, without any traditional numerical calculations. Traditionally, the group refractive index is calculat...

This article applies deep learning-accelerated inverse design algorithms and discovers a spectrum of photonic power dividers with exceptional performance metrics despite the simplicity in the design geometry. The deep learning models exhibit high precisions on the order of 10−6 to 10−8 for both TE and TM polarizations of light. These models enable...

Optical mode solving is of paramount importance in photonic design and discovery. In this paper we propose a deep deconvolutional neural network architecture for a meshless, and resolution scalable optical mode calculations. The solution is arbitrary in wavelengths and applicable for a wide range of photonic materials and dimensions. The deconvolut...

Plasmonic nanocavities have emerged as a promising platform for next-generation spectroscopy, sensing and photonic quantum information processing technologies, benefiting from a unique confluence of nanoscale compactness and integrability, ultrafast functionality and room-temperature viability. Harnessing their unprecedented optical field confineme...

Irreversible entropy production (IEP) plays an important role in quantum thermodynamic processes. Here, we investigate the geometrical bounds of IEP in nonequilibrium thermodynamics by exemplifying a system coupled to a squeezed thermal bath subject to dissipation and dephasing, respectively. We find that the geometrical bounds of the IEP always sh...

We present the localization mechanism of light in silicon Moiré structures and investigate the underlying physics of photonic flatband systems in the theory of resonant multiple light scattering.

Integrated avalanche photodetectors (APDs) are essential and ubiquitous devices in quantum photonics applications. While free-space APDs are a mature technology, the development of integrated APDs for visible light is still in its infancy. In this invited talk, we review our work on integrated photodetectors – the Germanium photodetector for O band...

We use the beam model of Doppler backscattering (DBS), which was previously derived from beam tracing and the reciprocity theorem, to shed light on mismatch attenuation. This attenuation of the backscattered signal occurs when the wavevector of the probe beam’s electric field is not in the plane perpendicular to the magnetic field. Correcting for t...

We use the beam model of Doppler backscattering (DBS), which was previously derived from beam tracing and the reciprocity theorem, to shed light on mismatch attenuation. This attenuation of the backscattered signal occurs when the wavevector of the probe beam's electric field is not in the plane perpendicular to the magnetic field. Correcting for t...

Integration of single-photon emitters (SPEs) with resonant photonic structures is a promising approach for realizing compact and efficient single-photon sources for quantum communications, computing, and sensing. Efficient interaction between the SPE and the photonic cavity requires that the cavity's resonance matches the SPE’s emission line. Here...

In this work, a full-wave partial element equivalent circuit (PEEC) model for 2-D periodic metallic structures is proposed. The mixed potential integral equations (MPIEs) with periodic Green’s function (GF) are interpreted as loop equations following Kirchhoff’s voltage law (KVL) in a circuit domain. The impact of gauge freedom in the MPIE on the c...

We present a judicious design approach for optimizing semiconductor nanocavities, starting from single photonic atoms to build photonic molecules functioning as high-performance nanocavities. This design approach is based on exact analytical solutions to the Maxwell equations for collective Mie resonances. Conceptually, we distinguish different con...

Optical mode solving is of paramount importance in photonic design and discovery. In this paper we propose a deep deconvolutional neural network architecture for a meshless, and resolution scalable optical mode calculations. The solution is arbitrary in wavelengths and applicable for a wide range of photonic materials and dimensions. The deconvolut...

Plexcitonic strong coupling has ushered in an era of room‐temperature quantum electrodynamics at the nanoscale. Realizing its potential applications from single‐molecule spectroscopy to room‐temperature quantum technologies on an industrial level requires scalable and mass‐producible plasmonic cavities that provide ease of access and control for qu...

Variational quantum algorithms (VQAs) are one of the most promising methods that can be implemented on noisy intermediate-scale quantum (NISQ) machines to achieve a quantum advantage over classical computers. This article describes the use of a VQA in conjunction with the finite difference method for the calculation of propagation modes of an elect...

Label-free optical biosensors using nanophotonic concepts have made substantial progress in the past few years because of their ability to realize fast, compact, and cost-effective chemical detection devices. Among those, high-refractive-index dielectric Mie nanoresonators hold promise for deep miniaturization of biosensing devices while maintainin...

Artificial intelligence (AI) techniques have been spreading in most scientific areas and have become a heated focus in photonics research in recent years. Forward modeling and inverse design using AI can achieve high efficiency and accuracy for photonics components. With AI-assisted electronic circuit design for photonics components, more advanced...

Integrated photodetectors are key building blocks of scalable photonics platforms. Many recent improvements have been made for integrated avalanche photodetectors (APDs) operating at infrared telecommunications wavelengths, but their visible-spectrum counterparts remain relatively unexplored. Here, we demonstrate PIN-doped silicon APDs for visible...

We demonstrate, using time domain finite difference simulations, that Smith-Purcell radiation can be precisely tailored. Spectral and spatial emission shaping is achieved by optimizing a grating parameterized by aperiodic sequence, which outperforms standard optimization schemes.

Plexcitonic strong coupling has ushered in an era of room-temperature quantum electrodynamics that is achievable at the nanoscale, with potential applications ranging from high-precision single-molecule spectroscopy to quantum technologies functional under ambient conditions. Realizing these applications on an industrial scale requires scalable and...

This paper proposes an investigating SARS-CoV-2 inactivation on surfaces with UV-C LED irradiation using our in-house-developed ray-tracing simulator. The results are benchmarked with experiments and Zemax OpticStudio commercial software simulation to demonstrate our simulator's easy accessibility and high reliability. The tool can input the radian...

Plexcitonic strong coupling between a plasmon-polariton and a quantum emitter empowers ultrafast quantum manipulations in the nanoscale under ambient conditions. The main body of previous studies deals with homogeneous quantum emitters. To enable multiqubit states for future quantum computing and network, the strong coupling involving two excitons...

Integration of single-photon emitters (SPEs) with resonant photonic structures is a promising approach for realizing compact and efficient single-photon sources for quantum communications, computing, and sensing. Efficient interaction between the SPE and the photonic cavity requires that the cavity's resonance matches the SPE emission line. Here we...

Variational quantum algorithms are one of the most promising methods that can be implemented on noisy intermediate-scale quantum (NISQ) machines to achieve a quantum advantage over classical computers. This article describes the use of a variational quantum algorithm in conjunction with the finite difference method for the calculation of propagatio...

Finding the ground state energy and wavefunction of a quantum many-body system is a key problem in quantum physics and chemistry. We study this problem for the long-range XY model by using the variational quantum eigensolver (VQE) algorithm. We consider VQE ansatzes with full and linear entanglement structures consisting of different building gates...

DOI:https://doi.org/10.1103/PhysRevA.104.019901

Quantum plasmonic systems suffer from significant decoherence due to the intrinsically large dissipative and radiative dampings. Based on our quantum simulations via a quantum tensor network algorithm, we numerically demonstrate the mitigation of this restrictive drawback by hybridizing a plasmonic nanocavity with an emitter ensemble with inhomogen...

Physical fields represent quantities that vary in space and/or time axes. Understanding the distribution of a field pattern is a key element in scientific discoveries and technological developments. In this article, by picking up the electromagnetic field of an optical waveguide as an example, we demonstrate how field patterns can be uncovered usin...

Strong light–matter interaction is at the heart of modern quantum technological applications and is the basis for a wide range of rich optical phenomena. Coupling a single quantum emitter strongly with electromagnetic fields provides an unprecedented control over its quantum states and enables high-fidelity quantum operations. However, single-emitt...

Integrated photodetectors are essential components of scalable photonics platforms for quantum and classical applications. However, most efforts in the development of such devices to date have been focused on infrared telecommunications wavelengths. Here, we report the first monolithically integrated avalanche photodetector (APD) for visible light....

This paper presents an approach for correcting phase reconstruction from the interferogram Diffraction phase microscopy (DPM) system if there exist artefacts around the defect features due to noises. By averaging local region around the artefacts of the unwrapped phase using a sliding window with iterative approach, the correct phase information ca...

Optical frequency conversion in semiconductor nanophotonic devices usually imposes stringent requirements on fabrication accuracy and etch surface roughness. Here, we adopt the concept of bound-state-in-continuum (BIC) for waveguide frequency converter design, which obviates the limitations in nonlinear material nano-fabrication and requires to pat...

We report the first monolithically integrated avalanche photodetector for visible light. We demonstrate a high gain-bandwidth product of 234 ± 25 GHz at 20V reverse bias, and open eye diagrams at up to 56 Gbps.

Quantum information processing often requires the preparation of arbitrary quantum states, such as all the states on the Bloch sphere for two-level systems. While numerical optimization can prepare individual target states, they lack the ability to find general control protocols that can generate many different target states. Here, we demonstrate g...

Subwavelength light-guiding optical devices have gained great attention in the photonics community because they provide unique opportunities for miniaturization and functionality of the optical interconnect technology. On the other hand, high-refractive-index dielectric nanoparticles working at their fundamental Mie resonances have recently opened...

Integrated photodetectors are essential components of scalable photonics platforms for quantum and classical applications. However, most efforts in the development of such devices to date have been focused on infrared telecommunications wavelengths. Here, we report the first monolithically integrated avalanche photodetector (APD) for visible light....

A highly efficient nanocavity formed by optically coupled nanostructures is achieved by optimization of the collective Mie resonances in a one-dimensional array of semiconductor nanoparticles. Analysis of quasi-normal multipole modes enables us to reveal the close relation between the collective Mie resonances and Van Hove singularities. Based on t...

A cascaded Mach-Zehnder interferometer based filter for coarse wavelength (de)multiplexing (CWDM) at the Oband is fabricated and tested on a silicon nitride on SOI platform. We characterize the chip-to-chip performance variability of the filter devices on a wafer. Using the optical measurement data, we apply Bayesian inference methods to estimate t...

Particle simulation has been widely used in studying plasmas. The technique follows the motion of a large assembly of charged particles in their self-consistent electric and magnetic fields. Plasmons, collective oscillations of the free electrons in conducting media such as metals, are connected to plasmas by very similar physics, in particular, th...

Quantum information processing often requires the preparation of arbitrary quantum states, such as all the states on the Bloch sphere for two-level systems. While numerical optimization can prepare individual target states, they lack the ability to find general solutions that work for a large class of states in more complicated quantum systems. Her...

A single photon in a strongly nonlinear cavity is able to block the transmission of the second photon, thereby converting incident coherent light into anti-bunched light, which is known as photon blockade effect. Photon anti-pairing, where only the entry of two photons is blocked and the emission of bunches of three or more photons is allowed, is b...

A single photon in a strongly nonlinear cavity is able to block the transmission of the second photon, thereby converting incident coherent light into anti-bunched light, which is known as photon blockade effect. On the other hand, photon anti-pairing, where only the entry of two photons is blocked and the emission of bunches of three or more photo...

With recent rapid advances in photonic integrated circuits, it has been demonstrated that programmable photonic chips can be used to implement artificial neural networks. Convolutional neural networks (CNN) are a class of deep learning methods that have been highly successful in applications such as image classification and speech processing. We pr...

Quantum networks provide a prominent platform for realizing quantum information processing and quantum communication, with entanglement being a key resource in such applications. Here we describe the dissipative transport protocol for entangled states, where entanglement stored in the first node of a quantum network can be transported with high fid...

div>With recent rapid advances in photonic integrated circuits, it has been demonstrated that programmable photonic chips can be used to implement artificial neural networks. Convolutional neural networks (CNN) are a class of deep learning methods that have been highly successful in applications such as image classification and speech process...

div>With recent rapid advances in photonic integrated circuits, it has been demonstrated that programmable photonic chips can be used to implement artificial neural networks. Convolutional neural networks (CNN) are a class of deep learning methods that have been highly successful in applications such as image classification and speech process...

The plasmonic systems suffer from a significant degree of decoherence from the intrinsic large dissipative and radiative damping mechanisms. Here we demonstrate that this restrictive drawback can be mitigated by hybridizing the plasmonic system with an emitter ensemble of inhomogeneously-broadened transition frequencies. We find that the coherent t...

In this article, we propose a trenched nanobeam cavity as an efficient on-chip optical system that can be used to enhance light emission from color centers in nanodiamonds. The trench is created at the center of nanobeam cavity, and it is filled with a nanodiamond. The trench—nanodiamond system significantly perturbs the electric field profile of t...

In article number 1900235 by Zhengtong Liu, Volkan Demir, Arseniy I. Kuznetsov, and co‐workers, full wavefront control of LED radiation in an integrated fashion is achieved by combining resonant cavities and metasurfaces. This method endows LED sources with the advanced functionalities enabled by metasurfaces, such as lensing, complex beam shaping...

A framework for community noise modelling is proposed, where noise sources are treated as their equivalent noise sources defined in a multidimensional space. The noise levels at measurement locations under different settings of noise sources in the space are predicted using a noise propagation simulator and the method of Design of Computer Experime...

We present an architecture to realize a convolutional neural network with integrated optics by using the Fourier transform property of star couplers. We show, in computer simulation, high accuracy image classification using the MNIST dataset.

We demonstrate a germanium-on-silicon vertical photodetectors for O-band wavelengths. The device shows <4 nA of dark current and responsivity of 0.87 A/W at -2V. The device bandwidth of 35 GHz is suitable for high speed applications.

The improvement of light‐emitting diodes (LEDs) is one of the major goals of optoelectronics and photonics research. LED integration to complex photonic devices requires precise control of the wavefront of the emitted light. Metasurfaces are spatial arrangements of engineered scatters that may enable this light manipulation capability with unpreced...

We propose a realization of the quantum switch for coherent light fields for the fiber-coupled microdisk cavities. We demonstrate by combining numerical and analytical methods that both in strong coupling and bad cavity limits it is possible to change a system's behavior from being fully transparent to being fully reflective by varying the amplitud...

Light-matter strong coupling is defined when the coupling strength exceeds the losses in the system, whereas ultrastrong coupling is not simply strong coupling with even larger coupling strength. Instead, ultrastrong coupling regime arises when the coupling strength is comparable to the transition frequency in the system. At present, ultrastrong li...

Quantum networks provide a prominent platform for realising quantum information processing and quantum communication, with entanglement a key resource in such applications. Here, we describe the transfer protocol for entangled states, where entanglement stored in the first node of quantum network can be transferred with high fidelity to the second...

The embodiment of the present invention provides a kind of DGS filter, printed circuit board and filter, is related to field of communication technology, DGS filter discrimination on multilayer printed circuit board can be improved. The DGS filter is for being filtered the signal transmitted on target cabling in the first routing layer in printed c...

An optical waveguide is the fundamental element in a photonic integrated circuit. This paper establishes a universal deep learning representation for the effective refractive index of an optical channel waveguide for the entire and usual parameter space for applications in photonics. The deep learning model is able to make precise predictions for w...

Integrated quantum photonics is recognized as a key enabling technology on the road towards scalable quantum networking schemes. However, many state-of-the-art integrated quantum photonics demonstrations still require the coupling of light to external photodetectors. On-chip silicon single-photon avalanche diodes (SPADs) provide a viable solution a...

Plasmon-polaritons are among the most promising candidates for next generation optical sensors due to their ability to support extremely confined electromagnetic fields and empower strong coupling of light and matter. Here we propose quantum plasmonic immunoassay sensing as an innovative scheme, which embeds immunoassay sensing with recently demons...

In article number 1900114, Ezgi Sahin, Dawn T. H. Tan, Benjamin J. Eggleton, and co‐workers describe how optical pulses propagating through a nonlinear ultra‐silicon‐rich nitride (USRN) grating experience high anomalous group‐velocity dispersion at the photonic band edge. The grating‐induced dispersion counteracts the large optical nonlinearity and...

Plasmon-polaritons are among the most promising candidates for next generation optical sensors due to their ability to support extremely confined electromagnetic fields and empower strong coupling of light and matter. Here we propose quantum plasmonic immunoassay sensing as an innovative scheme, which embeds immunoassay sensing with recently demons...

The improvement of light-emitting diodes (LEDs) is one of the major goals of optoelectronics and photonics research. While emission rate enhancement is certainly one of the targets, in this regard, for LED integration to complex photonic devices, one would require to have, additionally, precise control of the wavefront of the emitted light. Metasur...

Higher‐order soliton dynamics, specifically soliton compression and fission, underpin crucial applications in ultrafast optics, communications, and signal processing. Bragg solitons exploit the strong dispersive properties of periodic media near the photonic band edge. This enables soliton dynamics to occur in very short propagation distances, open...

Photon emission and absorption by an individual qubit are essential elements for the quantum manipulation of light. Here we demonstrate the controllability of spontaneous emission of a qubit in various electromagnetic environments. The parameter regimes that allow for flexible control of the qubit emission routes are comprehensively discussed. By p...