arXiv subjects

Chaoying Zhao

Publications and source records attributed to Chaoying Zhao.

16 recordsLinked to original sources

arXiv2026

Nonlinear dynamics of intra-cavity-field for periodically pump-modulated dual-coupled Kerr micro-ring cavities

We numerically investigate the long-time intra-cavity-field dynamics of a periodically pump- modulated pair of coherently coupled Kerr micro-ring resonators. Along a detuning scanning, fixed-phase stroboscopic trajectories change from recurrent regular state to states with positive maximum-Lyapunov growth. Long observation windows near the transition, where finite-time estimates converge slowly. The low- and high-detuning states both retain multi-mode Kerr-comb spectra, while their cycle-to-cycle field organization changes much more strongly. Spatiotemporal intensities, adjacent-cycle profiles, and full-field recurrence measures show a loss of one-period recurrence together with changes in the inter-resonator phase relation, coherent exchange, and dispersive intensity flow. We linearize the coupled equations around the long-time field and examine the growth of an infinitesimal perturbation. The resulting tangent-energy balance shows that the loss contribution changes little along the scanning, whereas the Kerr contribution increases and exceeds the loss magnitude in the high-detuning states with positive Lyapunov growth. A separate dimensional correspondence relates the normalized working range to Si3N4 micro-ring. These results provide a field-resolved description of the long-time dynamical change and its associated perturbation growth.

physics.optics↗

arXiv2026

Correlation-Assisted Odd-Parity Encoded Gates in Coupled Fluxonium Qubits under Non-Markovian TLS Noise

Correlated longitudinal noise can be partially converted into common-mode fluctuations in an oddparity two-qubit subspace. We analyze an encoded logical qubit formed by the states in two coupled fluxonium qubits. Projecting the exchange-coupled two-qubit Hamiltonian onto this subspace yields an effective logical Hamiltonian in which the exchange interaction drives XL rotations and the qubit detuning drives ZL rotations. We model correlated two-levelsystem (TLS) noise by using longitudinal stochastic processes with finite memory time and evaluate encoded-gate performance through the average gate fidelity. Within the projected model, positive spatial noise correlation suppresses the differential fluctuation and thereby improves the fidelity of encoded logical gates. We further compare Gaussian Ornstein-Uhlenbeck, Markovian, and randomtelegraph noise models and examine the role of logical dynamical decoupling. These results identify a noise-adapted control mechanism for odd-parity encoded operations in coupled fluxonium devices and motivate future multilevel simulations including leakage and pulse-level constraints.

quant-ph↗

arXiv2026

Multi-modes Bessel-Gaussian-Orbital Angular Momentum Beams Quantum Holography

We propose an orbital angular momentum (OAM) quantum holography scheme based on multi-mode Bessel-Gaussian (MBG) beams. Entangled photon pairs are generated through spontaneous parametric down-conversion (SPDC) process, and the axis prism parameters and topological charges of the idler photons are used for encoding to construct Bessel-Gaussian quantum selective holograms; then, the corresponding mode parameters carried by the signal photons are used for correlated decoding and information reconstruction. Theoretical analysis and numerical simulation results show that this scheme can effectively realize OAM quantum holography based on Bessel-Gaussian modes encoding. Compared with traditional single OAM encoding methods, our scheme introduce an additional mode degrees of freedom, which can enhance multiplexing dimension and encoding capacity; at the same time, relying on the non-classical correlation characteristics of entangled photons, quantum holography has a potential advantages in noise-resistance performance.

physics.optics↗

arXiv2026

Nonlinear dynamics of spatial soliton in a Kerr micro-ring

The input pump light field can be split into two transverse modes, after entering a AIN microring, which can generate rich nonlinear effects. The cross-phase modulation (XPM) effect in magnetic(TM) polarization mode can cause a refractive index alteration of the micro-ring, the electric(TE) polarization mode and TM polarization mode will display different values and generate a phase change. By adjusting the magnitude of the input TE polarization mode and TM polarization mode, we can achieve a series of phase distributions. By controlling the phase of the electromagnetic field, we can control orbital angular momentum (OAM). The traditional LLE does not take phase into account, in this paper, we obtain a generalized LLE includes phase case. Our research suitable for precision spectroscopy, optical communication links, and coherent information processing.

physics.optics↗

arXiv2025

Entanglement dynamics of multi-fluxonium-qubits under Non-Markovian TLS noise

The research on open quantum systems is important for both quantum computing and quantum sensing. So far, we can only use the main equation to make an approximate description. The dynamics of a single Fluxonium qubit under Markovian environment satisfied Lindblad Master Equation. In experiments, pulse sequence dynamic decoupling (DD) can enhance the coherence of qubits and effectively suppress noise. Two Fluxonium qubits sensitive to two-level systems (TLS) noise. TLS formed by material defects results in noise with significant non-Markovian characteristics. The dynamics of non-Markovian noise satisfied the post Markov Master Equation (PMME). The TLS noise spectrum is mainly concentrated in low frequencies, so traditional DD cannot effectively suppress TLS noise. The relaxation and dephasing behavior with a complex dynamic characteristics. Based on Ornstein-Uhlenbeck process, we put forward a novel DD sequence and design a TLS-tailored dynamical decoupling protocol by optimizing pulse locations to minimize noise power spectral overlap with the Lorentzian shape. Using PMME-consistent framework, we can obtain a stronger low frequency suppression and significantly prolong both Bell-based fidelity and entanglement. We explore specific DD design and precise modeling of entanglement dynamics under non-Markovian TLS noise. Our dynamical decoupling protocol can effectively improve entanglement gates fidelity in NISQ quantum devices.

quant-ph↗

arXiv2025

Nonlinear dynamics of soliton molecules in a Kerr micro-ring

The optical Kerr micro-ring provides an ideal platform for the study of dissipative optical solitons. Dissipative solitons are localized waves produced by a precise equilibrium between dispersion and nonlinearity, as well as gain and loss. Dissipative brilliant solitons are vulnerable to external noise,but dissipative dark solitons exhibit greater robustness against noise and losses. This study discusses the division of the input pump light field into transverse electric (TE) and transverse magnetic(TM) modes. TE mode generates bright solitons. TM mode forms dark solitons via cross-phase modulation (XPM), which induces a self-focusing effect. The bright and dark solitons bind into a soliton molecule pair through mutual interactions. We scan the entire detuning interval; within the positive small detuning interval, two modes simultaneously generate bright-dark soliton pair Turing roll states. Within the larger detuning interval, the excited Brillouin scattering noise induces a high suppression ratio (SR) between the dark and bright soliton pumps, which is unfavorable for the formation of the bright-dark soliton pair. The system provides a new multi-soliton manipulation scheme for optical communications. The soliton molecule pairs hold major implications for high precision measurement and all-optical controlling fields.

physics.optics↗

arXiv2024

Recognition of Schrodinger cat state based on CNN

We applied convolutional neural networks to the classification of cat states and coherent states. Initially, we generated datasets of Schrodinger cat states and coherent states from nonlinear processes and preprocessed these datasets. Subsequently, we constructed both LeNet and ResNet network architectures, adjusting parameters such as convolution kernels and strides to optimal values. We then trained both LeNet and ResNet on the training sets. The loss function values indicated that ResNet performs better in classifying cat states and coherent states. Finally, we evaluated the trained models on the test sets, achieving an accuracy of 97.5% for LeNet and 100% for ResNet. We evaluated cat states and coherent states with different {\alpha}, demonstrating a certain degree of generalization capability. The results show that LeNet may mistakenly recognize coherent states as cat states without coherent features, while ResNet provides a feasible solution to the problem of mistakenly recognizing cat states and coherent states by traditional neural networks.

quant-ph↗

arXiv2024

The Fano and EIT-like resonance characteristic of asymmetric double micro-ring resonator

By breaking the symmetrical arrangement of double micro-ring resonator, the formation mechanism and performance of reflection and transmission spectrum and optical field distribution are investigated. The reflection spectrum is Fano shape. The Fano resonance has an asymmetric and sharp resonance peak can be independently tuned by changing the asymmetric coupling factor of the first micro-ring. The transmission spectrum is electromagnetically induced transparency(EIT)-like shape. The (EIT)-like resonance can be independently tuned by changing the absorption factor and the phase shift factor of the second micro-ring. The Fano and EIT-like resonance have low loss and high near-field localization characteristics, our research has promising applications in optical communication and opto-electronic modulators.

physics.optics↗

arXiv2024

The multi-modes Bessel-Gaussian OAM hologram encoding based on convolutional neural networks

Multi-mode vortex light is a superposition of different orbital angular momentum (OAM) lights. However, as the number of OAM modes increases, the sampling constant changes. Using the traditional sparsely sampling will lead to severe loss of detail, reduced image resolution. To achieve high capacity and resolution of the OAM hologram, this paper prepares a multi-mode Bessel-Gaussian (MBG) selected hologram by stacking different mode combinations of BG phases on a MBG saved hologram in stages. Using a MBG beam with opposite combination parameters to illuminate the MBG OAM hologram, the target image can be reconstructed after the Fourier transform, and the sampling constant is flexible and controllable. The holograms encode MBG mode combination parameters. The additional degree of freedom provided by combining with MBG OAM beam offers more multiplexing channels and a higher security hologram. To further improve the quality of holograms, we first save the holograms and the corresponding MBG mode combination parameters when the quality of the obtained hologram is high based on Actor-Critic neural networks. Secondly, we gradually adjust the MBG mode combination parameters. Finally, we confirm the reasonable range of the MBG mode combination parameters.

physics.optics↗

arXiv2024

Study of multiple degrees of freedom entanglement in optical fiber

The orbital angular momentum (OAM) has attracted widespread attention due to its ability to carry information in multiple dimensions. However, a high-dimensional entanglement carrying OAM can be affected by environment and undergoes decoherence. Ensuring the stability and high fidelity of entangled states after transmission is a crucial part of quantum communication. How to control the entangled states are essential. In this paper, we produce the polarization entangled photon pairs by type I BBO crystals by means of spontaneous parametric down-conversion (SPDC), we achieve the polarization-OAM hybrid entangled states by q-plate (QP) by means of manipulating the multi-degrees of freedom of the quantum state after passing through the APD communication channel. The polarization entangled photon pairs have the characteristics of OAM. We use polarization degree of freedom to modulate OAM degree of freedom, our polarization-OAM hybrid entangled states can slow down the reduction of the fidelity in the during of transmission process. Our quantum states exhibit a superior level of fidelity contrast with the conventional situation. This method will provide a theoretical guidance for improving the transmission fidelity of OAM states in fiber.

quant-ph↗

arXiv2024

A broadband vortex beam generation by reflective meta-surface based on metal double-slit resonant ring

Recently, meta-surface(MS) has emerged as a promising alternative method for generating vortex waves. At the same time, MS also face the problem of narrow bandwidth, in order to obtain a board bandwidth, the MS unit cells structure become more and more complex, which will deduce many inconveniences to the preparation process of MS device. Therefore, we want to design a simple MS unit cell with a multi-frequency selection. In this paper, based on the principle of geometric phase, we design a simple reflective MS unit cell based on metal double-slit resonant ring. We elaborate on the resonance mechanism of the MS unit cell. Under the normal incidence of circularly polarized (CP) waves, the reflection coefficient of the same polarization was greater than 85%. By rotating the orientation angle of the resonator on the MS unit cell, the continuous 2pi phase coverage was satisfied in the frequency range of 0.52THz-1.1THz, and the relative bandwidth becomes 71.6%. Based on this, we construct a vortex generator by using a 15*15 MS unit array. The right-handed circularly polarized waves (RCP) and left-handed circularly polarized waves (LCP) are separately incident on MS with topological charges of l=1,2,3 under multiple resonant frequencies. The generated RCP vortex wave with topological charges of l=-1,-2,-3 and the generated LCP vortex wave with topological charges of l=1,2,3. The numerical simulation results exhibit our designed MS with multiple resonance outcomes can achieve a multi-broadband operation and generate a wide-band vortex beam. In addition, we also calculate the pattern purity. Through theoretical analysis and numerical simulation, we prove that our designed MS can generate a broadband vortex wave.

physics.optics↗

arXiv2024

Realization of two-qubit gates and multi-body entanglement states in an asymmetric superconducting circuits

In recent years, the tunable coupling scheme has become the mainstream scheme for designing superconducting quan tum circuits. By working in the dispersive regime, the ZZ coupling and high-energy level leakage can be effectively suppressed and realize a high fidelity quantum gate. We propose a tunable fluxonium-transmon-transmon (FTT) cou pling scheme. In our system, the coupler is a frequency tunable transmon qubit. Both qubits and coupler are capacitively coupled. The asymmetric structure composed of fluxonium and transmon will optimize the frequency space and form a high fidelity two-qubit quantum gate. By decoupling, the effective coupling strength can be easily adjusted to close to the net coupling between qubits. We numerical simulation the master equation to reduce the quantum noise to zero. We study the performance of this scheme by simulating the general single-qubit Xπ/2 gate and two-qubit (iSWAP) gate. In the bias point of the qubits, we achieve a single qubit gate with 99.99% fidelity and a two-qubit gate with 99.95% fidelity. By adjusting the nonlinear Kerr coefficient of fluxonium to an appropriate value, we can achieve a multi-body entanglement state. We consider the correlation between the two qubits and the coupler, and the magnetic flux passing through one qubit has an effect on the other qubit and the coupler. Finally, we analyze the quantum correlation of the two-body entanglement state.

quant-ph↗

arXiv2023

Investigation of the characteristics of the electromagnetic induction transparent-like spectrum with counter-propagating waves coupling mechanism for waveguide and micro-ring coupled system

In this paper, a new counter-propagation waves coupling mechanism is proposed which is expected to realize an electromagnetically induced transparency (EIT)-like effect. Comparing the travelling waves coupling mechanism (see J. Mod. Opt. 2015,62:313-320 [9]) with the counter-propagating waves coupling mechanism, we find out that the transparency window breadths of transmission spectra are greatly enhanced and the corresponding phase shift spectra possess a flat profile or a square profile. Our numerical simulated results are in good agreement with the theoretical analysis. The EIT-like effect can significantly reduce the group velocity near the edge of the square profile transparent window. We believe that the counter-propagating waves coupling mechanism is particularly beneficial for the realization of active manipulation of slow light devices (such as delay lines) required in the conventional EIT scheme. In the vicinity of the transparency peak, we can obtain a large group delay, may gain more significant potential applications in slow-light transmission and optical storage.

physics.optics↗

arXiv2022

Investigation of the characteristics of the dual-band electromagnetic induction transparent-like terahertz spectrum in a grating-like structure

In this paper, a new structure is proposed which is expected to realize dual-band electromagnetically induced transparency (EIT)-like effect in terahertz spectrum. It can be regarded as a metamaterial of grating-like elements composed of dual-band U-shaped resonators. The near-field coupling between bright modes can produce EIT-like effect. After optimizing the parameters, our numerical simulated results are in good agreement with the theoretical analysis. The EIT-like effect can significantly reduce the group speed near the transparent window, may gain more significant potential applications in slow-light transmission and optical storage.

physics.optics↗

arXiv2021

Modulation instability of Kerr optical frequency combs in dual-coupled optical cavities

Kerr optical frequency combs generated in a coherently driven Kerr nonlinear resonator has the potential for a wide range of applications. However, in a single cavity which is a widely adopted configuration for Kerr optical frequency combs generation, modulation instability is suppressed in normal dispersion regime and the pump-to-comb conversion efficiency is extremely low for a single dissipative Kerr soliton in anomalous dispersion regime. Dual-coupled cavities have been proposed to generate Kerr optical frequency combs in normal dispersion regime, and have potential to remarkably increase conversion efficiency for Kerr optical frequency combs. Here, we investigate modulation instability and Kerr optical frequency-comb formation in dual-coupled cavities. Based on solutions of the continuous-wave steady state, we obtain a quadric algebraic equation describing the modulation instability gain, and we find that it is intensely influenced by the group velocity mismatch between the two cavities. Our numerical simulations demonstrate that platicons can be generated via pump scanning scheme for the case that both the two cavities possess normal dispersion, and a single dissipative Kerr soliton can be generated in the cavity with anomalous dispersion while the dispersion of the other cavity is normal. Our analysis of modulation instability provides a powerful tool for Kerr optical frequency-comb generation via pump modulation and cavity detuning tuning scheme in dual-coupled cavities.

physics.optics↗

arXiv2020

Frequency-domain model of optical frequency-comb generation in optical resonators with second- and third-order nonlinearities

We developed a frequency-domain model describing optical frequency-comb generation in optical resonators with second- and third-order nonlinearities. Compared with time-domain models, our model in principle allows one to express the cavity dispersion accurately, avoiding the dispersion being truncated beyond a certain order. Moreover, the frequency-domain model can readily include frequency dependence of system parameters, such as the linear absorption and the cavity coupling ratio. To demonstrate the validity of our model, we numerically simulated quadratic combs in a singly resonant second-harmonic generation cavity and Kerr combs in a micro-resonator as two examples. The simulated results obtained from the frequency-domain model agree well with those given by previous time-domain models. A system containing both second- and third-order nonlinearities can give rise to many novel physical dynamics. The developed frequency-domain model will contribute to understanding optical frequency-comb generation assisted by multi-order nonlinear processes in various optical resonators.

physics.optics↗