Abstract Robust, tightly localized photonic modes are essential for scalable on-chip quantum information processing, including multi-plane (3D-integrated) photonic platforms in which multiple planar waveguide layers are vertically stacked and coupled. Here, we present a comprehensive study of three three-dimensional fractal photonic architectures, 3D Cantor dust, Vicsek fractal, and Sierpinski sponge, each discretized into dielectric voxels and modeled in a voxel-graph tight-binding surrogate with exponentially decaying evanescent-hopping couplings. We examine two imperfection classes: on-site refractive-index disorder (amplitude up to 10%) and stochastic voxel deletions (defect rate up to 2%). In a classical eigenanalysis (over 10 000 parameter combinations of waveguide width, layer thickness, baseline coupling, decay constant, and defect rate) we compute the central spectral spacing $$\Delta \lambda $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>Δ</mml:mi> <mml:mi>λ</mml:mi> </mml:mrow> </mml:math> (a finite-structure stopband proxy) and the inverse participation ratio, and demonstrate via ANOVA/Tukey HSD (adjusted $$p\ll 10^{-3}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>p</mml:mi> <mml:mo>≪</mml:mo> <mml:msup> <mml:mn>10</mml:mn> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>3</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> ) that 3D Cantor dust yields the largest mean central spacing and highest inverse participation ratio across depths and parameter ranges. Because the canonical Cantor-dust voxelization is disconnected under the unit-neighborhood coupling rule used in this paper, its high IPR should be interpreted as isolation-dominated localization within this surrogate. We additionally map the tight-binding coupling graphs to 2-local qubit Hamiltonians in the single-excitation manifold (one qubit per retained site), and we validate a variational quantum eigensolver workflow on a 2-qubit SSH dimer and on 4–8-qubit fractal subgraphs; the qubit counts, optimization objective, shot-based measurement model, and resource scaling with fractal iteration depth are stated explicitly. Our work positions 3D Cantor dust as a favorable multi-scale platform for graph-spectral stopband engineering and robust mode localization in tight-binding surrogates, motivating targeted full-wave electromagnetic validation and device-level studies of planar-mask implementations (stacked 2D fractal layers with vertical couplers) for 3D-integrated on-chip deployment.

Abstract The performance of high-speed optical communication systems is constrained by Chromatic Dispersion (CD), which poses a significant challenge to data transmission integrity. This paper proposes a method to mitigate CD using cascaded Apodized Fiber Bragg Gratings (AFBGs). The apodization function plays a crucial role in dispersion mitigation, effectively reducing side lobes in the Fiber Bragg Grating (FBG) reflection spectrum. The proposed model employs two cascaded stages, each utilizing an apodization function that merges the Nuttall and Bartlett profiles. This model is investigated to enhance FBG performance and is compared with other apodization functions. Using an induced refractive index of 2.8 × 10⁻⁵ and a grating length of 60 mm, numerical results show that the Nuttall-Bartlett apodization function achieves the narrowest Full Width at Half Maximum (FWHM) of 0.027 nm—a 20.48% improvement over the uniform model—while maintaining a reflectivity of 99.12%. The performance of the proposed model is further evaluated through the quality factor (Q-factor) and Bit Error Rate (BER), yielding an improvement in both metrics over the uniform model.

In this study, we propose a micro neutron star-like gravity model to explain the phenomenon of superluminal response in quantum entanglement experiments. In our model, measurements of the spin state of one electron may cause that electron to emit ultralong-wavelength photons to inform another entangled electron. Therefore, one electron will be connected to another electron through the Coulomb interaction of ultra-low energy photons. The scattering of ultra-long wavelength light can be ignored, and only the super-strong gravity around the atomic nucleus is considered. In this model, the ultra-long wavelength light close to the atomic nucleus is mainly affected by the super-strong gravitational field of each atomic nucleus, and the time passing through each atomic nucleus will be shortened by Δt on average, and a superluminal response is finally observed. Our model does not violate special relativity but discusses the measurements between different reference coordinates within the framework of general relativity.