Deep learning based on the loss metric for inverse design of photonic resonators.

We have proposed and implemented what we believe to be a novel metric for providing a more effective similarity evaluation to the deep learning algorithms used for the inverse design of resonant photonic devices. The conventional loss functions, such as mean square error (MSE) and mean absolute error (MAE), are incapable of recognizing the characteristics of resonances accurately. Therefore, we have calculated the time domain complex vectors through the Fourier transform (FT) of the original desired spectra, and the complex results containing amplitude and phase could distinguish the resonances more significantly.

Accurate time-domain and frequency-domain co-simulation approach for OEICs design with Verilog-A.

Optoelectronic integrated circuits (OEICs) have enhanced integration and communication capabilities in various applications. With the continued increase in complexity and scale, the need for an accurate and efficient simulation environment compatible with photonics and electronics becomes paramount. This paper introduces a method using the Verilog-A hardware language in the electronic design automation (EDA) platform to create equivalent circuit and compact models for photonic devices, considering their dispersion, polarization, multimode, and bidirectional transmission characteristics.

Inverse Design of Nanophotonic Devices Using Generative Adversarial Networks with the Sim-NN Model and Self-Attention Mechanism.

The inverse design method based on a generative adversarial network (GAN) combined with a simulation neural network (sim-NN) and the self-attention mechanism is proposed in order to improve the efficiency of GAN for designing nanophotonic devices. The sim-NN can guide the model to produce more accurate device designs via the spectrum comparison, whereas the self-attention mechanism can help to extract detailed features of the spectrum by exploring their global interconnections. The nanopatterned power splitter with a 2 μm × 2 μm interference region is designed as an example to obtain the average high transmission (>94%) and low back-reflection (<0.

Modal analysis of transverse Anderson localization based on the imaginary distance BPM.

The transverse Anderson localization (TAL) can always be observed in one-dimensional (1D) disordered systems as long as the transverse dimension is significantly larger than the localization length. This paper presents a detailed modal analysis in one particular realization of the 1D disordered optical waveguides with wavelength-scale feature size based on the imaginary distance beam propagation method (BPM). The localized modes are independent of the physical properties of the external excitation.

Broadband nonreciprocal spoof plasmonic phase shifter based on transverse Faraday effects.

Spoof surface plasmon polaritons (SSPPs) have aroused widespread concern due to their strong ability in field confinement at low frequencies. For miniaturized integrated circuits, there is a pressing need for nonreciprocal spoof plasmonic platforms that provide diode functionalities. In this letter, we report the realization of nonreciprocal phase shifting in SSPPs using the transverse Faraday effect.

Continuous current-injected waveforms shaping for suppressing relaxation oscillations of direct modulation based on equivalent circuit model.

An improved technique of continuous shaping current-injected waveforms based on the single-mode rate equations is proposed to suppress relaxation oscillations (ROs) from direct modulation of distributed feedback laser (DFB). The signal expression of shaping current is deduced theoretically from the dependence of DFB desired output waveforms in detail, and the specific parameters derivation of the different polynomial degree is also discussed necessarily. Furthermore, a polynomial p-function with inverse operation is adopted to construct the Fourier series corresponding to injection current waveform signal.

Investigation of the disordered optical fiber with wavelength-scale feature size mediated by transverse Anderson localization.

A narrow beam propagating through the disordered optical fiber first undergoes diffusive broadening, until its width becomes comparable to the localization length. The study of numerical algorithms and statistical methods in the simulation analysis process of disordered optical fibers demonstrates that the influence of polarization characteristics and transverse grids on calculation errors is critical for statistical numerical simulation in disordered systems. We performed a detailed numerical analysis of the effect of different design parameters in disordered fibers on the localization effect-that is, the localization length, including the refractive index contrast, feature size, and fill-fraction.

Efficient modeling method for emitting focusing grating coupler based on complex mode matching and effective index method.

In this paper, an efficient modeling method for a photonics-focusing grating coupler is proposed and studied. The focusing grating coupler can be divided into two parts: the cylindrical coordinate slab waveguide and the Cartesian coordinate slab waveguide. Using the cylindrical slab modes and the two-dimensional complex mode-matching method, we can obtain the efficient compact model for the focusing grating coupler.

Giant nonreciprocal transmission in low-biased gyrotropic metasurfaces.

Strong magneto-optical effect with low external magnetic field is of great importance to achieve high-performance isolators in modern optics. Here, we experimentally demonstrate a significant enhancement of the magneto-optical effect and nonreciprocal chiral transmission in low-biased gyrotropic media. A designer magneto-optical metasurface consists of a gyrotropy-near-zero slab doped with magnetic resonant inclusions.

Optically transparent metamirror with broadband chiral absorption in the microwave region.

Chiral metamirror is one of the recently developed metadevices which can reflect designated circularly polarized waves, mimicking the exoskeleton of iridescent green beetles. Here, an optically transparent metamirror that can absorb microwave chiral photons in a broadband spectrum is demonstrated. A coupled mode theory is adopted to reveal the underlying physics for the improved bandwidth performance.

Enhancing the magneto-optical effects in low-biased gyromagnetic media via photonic doping.

Enhancing nonreciprocal light-matter interaction at subwavelength scales has attracted enormous attention due to high demand for compact optical isolators. Here, we propose a significant enhancement of the magneto-optical effect in low-biased gyromagnetic media via photonic doping. Magnetic particles immersed in a gyrotropy-near-zero medium act as dopants that largely modify the macroscopic gyromagnetic effects as well as the gyroelectric ones.