Dark Mode Research Articles

Active control of an electromagnetically induced transparency analogue in a coupled dual bound states in the continuum system integrated with graphene.

Electronically induced transparency (EIT) is a coherent optical phenomenon that induces interference within atoms, allowing certain specific frequencies of light to pass through atomic media without being absorbed. However, EIT systems face challenges related to narrow transparency windows and precise control of slow light. We propose an interference structure based on a coupled dual bound states in the continuum (BIC) system to emulate the EIT-like effect. By integrating quasi-BIC (bright mode) with BIC (dark mode), our design successfully achieves an EIT-like effect in a narrow bright mode with a full width at half maximum (FWHM) of less than 1 nm. Its notable features are the bright mode's wide tunability achieved through structural parameter adjustment and a significant group delay of up to 14.43 ps. Additionally, integrating graphene into the BIC structure introduced a form of active tunability akin to the EIT-like effect. We numerically calculate the coupling structure, and its intrinsic mechanism is analyzed. Analysis based on coupled-mode theory confirms that this active modulation primarily stems from changes in the BIC structure's loss. Due to its special frequency selectivity and insensitivity to the polarization of the light source, this narrow-band EIT-like structure is particularly suitable for high-precision optical sensing and spectroscopy. The significant group delay of this structure enhances the interaction between light and matter, improving the accuracy and efficiency of optical signal control and data transmission, opening up new avenues for slow light applications and making significant progress in the development of active tunable optical switches and modulators.

A high Q-factor metamaterial sensor based on electromagnetically induced transparency-like

This paper proposes an electromagnetically induced transparency-like (EIT-like) metamaterial with a high-quality factor (143.54), which is composed of a square ring resonator (SRR) and a cross-shaped resonator (CR). The designed metamaterial generates a sharp transparency peak at 15.79 GHz. The electric field distributions reveal that appearance of the transparency window results from the coupling between bright mode and dark mode. Moreover, analysis of the surface current distributions verifies that the EIT-like effect is induced by the destructive interference of the electric dipoles . Furthermore, the metamaterial is equated to a circuit model, which provides a better fit to the simulated transmission spectrum. These theories fully explain the generation mechanism of the EIT-like phenomenon. In addition, the EIT-like metamaterial is able to detect the dielectric constant of the target analyte (glucose solution), and the sensing performance is evaluated. The results demonstrate that the sensitivity (S) is 4.80 GHz R−1IU−1 and the figure of merit (FOM) reaches 43.71. The proposed EIT-like metamaterial shows prominent sensing abilities, consequently it has potential applications in environmental monitoring, biological and chemical measurements.

Specific detection of CA242 by antibody-modified chiral symmetric double “N” metasurface biosensor

In this work, a biosensor based on Fano resonance metasurface is proposed for the specific detection of CA242 which is a typical marker of pancreatic cancer. The biosensor consists of a chiral symmetric plasma double “N” structure, which utilises coherent coupling of bright and dark modes to generate Fano resonance, achieving suppression of radiation loss, concentrating and storing energy more efficiently in the structure, and contributing to increased sensitivity to changes in ambient refractive index, resulting in a sensitivity of the sensor of up to 842.8 nm /RIU. After a series of antibody functionalization modifications, the metasurface has become an immune biosensor that can specifically detect the tumor marker CA242 of pancreatic cancer. The detection of mixed and single antigen solutions with different concentrations has verified the high sensitivity, high specificity, and high linear relationship of the biosensor to CA242, and the detection limit is as low as 0.0692 ng/mL. It is superior to other common methods and breaks the traditional disadvantages of lower detection accuracy and greater damage in tumour detection methods. The detection of the wavelength shift of localized surface plasmon resonance in plasma metasurface has been successfully applied to the highly sensitive detection of tumor markers. This study demonstrates the sensitivity and maneuverability of the chiral symmetric double “N” plasmonic metasurface biosensor, suggesting the potential application of metamaterials in biosensing based on environmental refractive index changes.

Pembuatan Aplikasi Persediaan Barang Berbasis Web Pada PT. Bayan Resources Tbk

This research aims to design and implement a web-based Goods Inventory Information System at PT Bayan Resources Tbk. The company faces challenges in inventory management, such as stock uncertainty, variations in order cycle time, and operational efficiency levels that need to be improved. Waterfall method is used as a framework for system development, with stages of requirement analysis, design, implementation, testing, and maintenance. The system is designed to improve operational efficiency through integration of inventory data, order management, and item tracking. The result is a web-based application with features such as a secure login page, informative dashboard, master data management, efficient input of incoming and outgoing goods, and careful user control. With the implementation of dark mode, the system gives users the flexibility to customize the display according to their preferences. Users can easily access, track, and analyze inventory data, supporting faster and more accurate decision-making for the company.

Electromagnetically induced transparency based on spoof localized surface plasmons

A pair of resonators are used to realize multiple electromagnetically induced transparency-like (EIT-like) transmission peaks operating in the microwave band, with the bright and dark modes being symmetric double-ellipsoids and spoof localized surface plasmons. The simulation and test results reveal that the EIT-like metamaterial may generate three transparent EIT-like transmission peaks in the 9~12 GHz frequency range. Following that, we propose a plasmonically induced transparency refractive index sensor that operates in the IR range. The group delay in this sensor has broad applicability in diverse surface sensing based on EIT-like metamaterials.

Structural and Optical Properties of Sol–Gel-Spin Coating Nanostructured Cadmium Zinc Nickel Phosphate (CZNP) Film and the Current Transport Properties of CZNP/p-Si-Based Diode

In this work, the growth of CdZnNiPO (CZNP) thin films on glass and p-Si substrates using the sol–gel spin coating method was successfully achieved. The structure, and morphology of the CZNP films were analyzed using XRD and FE-SEM. The optical absorbance behavior, energy gap, refractive indices, optical dielectric, optical conductivity, and optical electronegativity of the films were studied using the UV–Vis optical spectroscopy technique. XRD analysis shows that zinc phosphate accommodates cadmium ions by replacing zinc ions in the unit cell, resulting in oxygen vacancies that maintain charge neutrality. Scanning electron microscope images reveal the presence of a highly interconnected and well-organized nano CZNP framework. The optical absorption studies of CZNP films were conducted in the wavelength range of 190–2500 nm. The results show both direct and indirect energy band gaps of 1.69 and 2.89 eV, respectively, were employed in the prepared system. The current–voltage-temperature (I-V-T) characteristics of the CZNP/p-Si junction was analyzed in dark mode. The device transport ideality factor, barrier height, and series resistance were identified.

Dual dynamically tunable terahertz graphene-based plasmonic induced transparency and slow light effects

A novel single-layer graphene-based structure is designed in this article. This structure consists of two graphene strips and two graphene blocks. The components of this structure generate two bright modes and one dark mode in the terahertz region, and these three modes undergo destructive interference, leading to the phenomenon of double plasmonic induced transparency. The graphene of this structure has continuity, and the Fermi level can be adjusted by adjusting the bias voltage applied to the structure. Compared with those discontinuous structures, it is easier to achieve tuning function. The structure uses the finite-difference time-domain for data simulation, uses the coupled mode theory for theoretic calculation, and compares the transmission spectra obtained by the two methods. Through observation, it can be found that the frequency positions of the peaks and dips of the simulated transmission spectrum increase with the increase of the Fermi level, showing a perfect linear relationship, which indicates that this structure has great prospects in the modulator. In addition, the structure has achieved good results in the slow light effect, and after measurement, the peak values of group index and group delay can reach up to 380 and 0.241 ps, respectively. By utilizing these advantages, this structure can provide more possibilities for the development and research of slow light fields.

Linear Polarization Conversion Based on Symmetry‐Breaking in an Electromagnetically Induced Transparency Structure

AbstractTraditional polarization converters suffer from drawbacks such as significant thickness and high losses, which limit their practical applications. This study introduces a novel metamaterial structure that combines electromagnetically induced transparency (EIT) with linear polarization conversion to overcome these limitations. By harnessing the properties of EIT, this structure achieves low‐loss polarization conversion. The mechanism behind this is the generation of an EIT effect through the coupling of the light and dark modes. Additionally, this study focuses on introducing a slight vertical polarization symmetry disruption and inducing the excitation of small components within the dipole of the EIT structure to achieve close‐to‐complete cross‐polarization conversion. The effect of asymmetry on the polarization conversion rate is also explored. This study offers an innovative approach to designing low‐loss polarization converters utilizing EIT technology.

Bright and dark plasmon resonance of Ag nanorod dimers

In this paper, plasmon resonances arising from the interaction between two closely spaced nanoparticles have been investigated by the finite difference time domain method. We report that the plane wave directly excites the bright mode and dark mode in the symmetric Ag nanorod dimers. We study the spectral properties of plasmonic nanorod systems by selectively tailoring the nanorod geometry parameters and interparticle gap distance. We also study the modulation of the geometry parameters and gap distances of nanorods on the charge density and electric field distributions of both the resonance modes. We believe that unlocking these properties will inspire further exciting developments in quantum mechanical effects and sub-nanometer scale photonics.

Search for Dark Photon in e+e− → A′A′ Using Future Collider Experiments

The Standard Model (SM) does not provide an information for 26% of dark matter of the universe. In the dark sector, dark matter is supposed to be linked with the hypothetical particles called dark photons that have similar role to photons in electromagnetic interaction in the SM. Besides astronomical observation, there are studies to find dark matter candidates using accelerators. In this paper, we searched for dark photons using future electron-positron colliders, including Circular Electron Positron Collider (CEPC)/CEPC, Future Circular Collider (FCC-ee)/Innovative Detector for Electron-positron Accelerator (IDEA), and International Linear Collider (ILC)/International Large Detector (ILD). Using the parameterized response of the detector simulation of Delphes, we studied the sensitivity of a double dark photon mode at each accelerator/detector. The signal mode is double dark photon decay channel, e+e− → A’A’, where A’ (dark photon with spin 1) decaying into a muon pair. We used MadGraph5 to generate Monte Carlo (MC) events by means of a Simplified Model. We found the dark photon mass at which the cross-sections were the highest for each accelerator to obtain the maximum number of events. In this paper we show the expected number of dark photon signal events and the detector efficiency of each accelerator. The results of this study can facilitate in the dark photon search by future electron-positron accelerators.

Terahertz sensor based on plasmon-induced transparency in a carbon nanotube metamaterial

In this paper, the plasmon-induced transparency (PIT) effect based on a carbon nanotube (CNT) resonator structure is achieved. An array of two split ring resonators (SRRs) and a cut wire (CW) resonator are utilized to form the proposed metamaterial. A PIT transparency window is achieved under a TM polarization terahertz light. Results show that the PIT effect is originated from the near-field coupled of the bright mode and dark mode. A coupled harmonic oscillator model is used to describe the near-field coupling between the bright mode and subradiant mode, and the results agree well with the FDTD simulation. The effect of geometrical sizes, like structure period, the radius and the splitting degree of the split ring resonator, the length of the cut wire resonator, and the coupling distance on the PIT window is analyzed in detail. Besides, the sensing and slow light performance of the proposed CNT metamaterial are studied, a maximum sensitivity of 0.74 THz RIU, and a time delay of 0.54 ps are obtained. Therefore, the proposed CNT-based device can be applied to the PIT effect, near-infrared modulators, slow light devices, sensors, and other fields.

A First Look at Dark Mode in Real-world Android Apps

Android apps often have a “dark mode” option used in low-light situations, for those who find the conventional color palette problematic, or because of personal preferences. Typically developers add a dark mode option for their apps with different backgrounds, text, and sometimes iconic forms. We wanted to understand the actual provision of this dark mode in real-world Android apps through an empirical study of posts from Stack Overflow and real-world Android app analysis. Using these approaches, we identified the aspects of dark mode that developers implemented as well as the key difficulties they experienced in implementing it. We performed a quantitative analysis using open-coding of more than 300 discussion threads to create a taxonomy regarding the aspects discussed by developers with respect to dark mode in Android. Our quantitative analysis of over 6,000 Android apps highlights which dark mode features are typically provided in Android apps and which aspects developers care about during dark mode design. We also examined four app development support tools to see how well they aid Android app development for dark mode. From our analysis, we distilled some key lessons to guide further research and actions in aiding developers with supporting users who require such assistive features. For example, developers should be aware of the potential risks in using unsuitable dark mode design schema and researchers should take dark mode features into consideration when developing app development support tools.

Designing and Implementing a Dark Mode for a Library Website

Dark mode, also known as night mode, is an alternative way of viewing content on a webpage. Rather than having dark text on a light background, dark mode displays light text on a dark background. In fall 2022, the Indiana University–Purdue University Indianapolis (IUPUI) University Library launched a dark mode as an option for web users. We present some considerations for design and implementation for those interested in adding a dark mode to their website.

Unlocking microalgal host-exploring dark-growing microalgae transformation for sustainable high-value phytochemical production.

Microalgae have emerged as a promising, next-generation sustainable resource with versatile applications, particularly as expression platforms and green cell factories. They possess the ability to overcome the limitations of terrestrial plants, such non-arable land, water scarcity, time-intensive growth, and seasonal changes. However, the heterologous expression of interested genes in microalgae under heterotrophic cultivation (dark mode) remains a niche area within the field of engineering technologies. In this study, the green microalga, Chlorella sorokiniana AARL G015 was chosen as a potential candidate due to its remarkable capacity for rapid growth in complete darkness, its ability to utilize diverse carbon sources, and its potential for wastewater treatment in a circular bioeconomy model. The aims of this study were to advance microalgal genetic engineering via dark cultivation, thereby positioning the strain as promising dark-host for expressing heterologous genes to produce high-value phytochemicals and ingredients for food and feed. To facilitate comprehensive screening based on resistance, eleven common antibiotics were tested under heterotrophic condition. As the most effective selectable markers for this strain, G418, hygromycin, and streptomycin exhibited growth inhibition rates of 98%, 93%, and 92%, respectively, ensuring robust long-term transgenic growth. Successful transformation was achieved through microalgal cell cocultivation with Agrobacterium under complete darkness verified through the expression of green fluorescence protein and β-glucuronidase. In summary, this study pioneers an alternative dark-host microalgal platform, using, Chlorella, under dark mode, presenting an easy protocol for heterologous gene transformation for microalgal host, devoid of the need for expensive equipment and light for industrial production. Furthermore, the developed genetic transformation methodology presents a sustainable way for production of high-value nutrients, dietary supplements, nutraceuticals, proteins and pharmaceuticals using heterotrophic microalgae as an innovative host system.

Strong coupling of plasmonic bright and dark modes with two eigenmodes of a photonic crystal cavity.

Dark modes represent a class of forbidden transitions or transitions with weak dipole moments between energy states. Due to their low transition probability, it is difficult to realize their interaction with light, let alone achieve the strong interaction of the modes with the photons in a cavity. However, by mutual coupling with a bright mode, the strong interaction of dark modes with photons is possible. This type of mediated interaction is widely investigated in the metamaterials community and is known under the term electromagnetically induced transparency (EIT). Here, we report strong coupling between a plasmonic dark mode of an EIT-like metamaterial with the photons of a 1D photonic crystal cavity in the terahertz frequency range. The coupling between the dark mode and the cavity photons is mediated by a plasmonic bright mode, which is proven by the observation of a frequency splitting which depends on the strength of the inductive interaction between the plasmon bright and dark modes of the EIT-like metamaterial. In addition, since the plasmonic dark mode strongly couples with the cavity dark mode, we observes four polariton modes. The frequency splitting by interaction of the four modes (plasmonic bright and dark mode and the two eigenmodes of the photonic cavity) can be reproduced in the framework of a model of four coupled harmonic oscillators.

Breaking down process barriers: ZnSe/CdSe composite catalysts drive enhanced catalytic properties and modified membrane structures for removing humic acid from aqueous environments

In the present research, with the aim of removing humic acid from wastewater, photo-catalytic membrane reactor was utilized. Single-component catalysts including ZnSe, CdSe, as well as composite catalyst (ZnSe/CdSe) were deposited in the surface layer of polysulfone membrane via photo-grafting method, whereby ZniCdjM11i and j are ZnSe and CdSe loading concentration level membranes were synthesized. The results indicated that the ZnSe/CdSe due to its shorter bandgap, had a more effective role in the grafting process and hence adjusting the membrane pore size. The pore size of Zn4Cd4M was smaller than that of Zn4Cd0M and Zn°Cd4M, and hence the humic acid separation in the dark mode by Zn4Cd4M was 80 %, which is about 10 % greater than the value obtained by Zn4Cd0M and Zn°Cd4M. The ZnSe/CdSe due to its less photoluminescence emission, proved to be more effective in photocatalytic reactions compared to the single component catalysts. The extent of photocatalytic degradation of humic acid in the presence of UV-radiation by the Zn°Cd4M, Zn4Cd0M, and Zn4Cd4M was reported 80, 84, and 96 % respectively. Overall, due to the smaller pore size, shorter bandgap, and lower recombination, TOC removal by the Zn4Cd4M (containing composite catalyst) was reported 98 %, while this value for the Zn4Cd0M and Zn°Cd4M was reported 60 and 66 % respectively.

Developing checkerboard cross element metasurface with multi-Fano response for sensing in the infrared spectrum

A novel metasurface has been developed based on a checkerboard formation for optical biosensing in the infrared spectrum (10 μm) to diagnose cancer cells in the early stages. The design incorporates phase control in each quarter of the checkerboard metasurface to achieve Fano and mufti Fano responses. The resonances are provided by a self-similar arrangement of cross elements. The interaction between these elements enables hybridization between bright modes, resulting in both bright and dark modes to produce the desired Fano response. The final structure exhibits a quad-band Fano response, and the four steps of the design process are presented and discussed. The physics behind the proposed metasurface is described using the electric field and circuit model. The designed structure is optimized for the frequency range of 10–40 THz. The sensitivity, Q-factor, and Figure of Merit (FOM) are examined for each resonance to evaluate the material under test. The extracted results demonstrate that the proposed metasurface allows for the identification of unknown materials with higher accuracy compared to conventional metasurfaces with a single resonance. The maximum Q-factor achieved is approximately 354, and the maximum FOM is obtained at 47.4 RIU−1. Additionally, the sensitivity factor reaches a maximum value of 3657 nm/RIU, further enhancing the sensing capabilities of the metasurface.

Sameness and Solidarity in the Supervisory Environment

Supervisees who have experienced disturbing therapeutic incidents that undermined their professional self‐experiences need a supervisory environment of sameness and solidarity to process and learn from these lived experiences. To create such an environment, supervisors need to minimize the sense of safety asymmetry between themselves and their supervisees by awakening to the ‘dark,’ ominous truths of professional life. This process is facilitated by summoning memories of therapeutic experiences of failure, vulnerability and frustration at having insufficient time to achieve wished‐for therapeutic goals. Awakening to these truths inspires a dark experiential mode that helps the supervisor share the supervisee's destiny and existential anxiety. Despite the contradiction between the dark and the playful, experiential modes, both are essential for creatively understanding the supervisee's disturbing therapeutic experiences and learning from them. Moreover, when these modes are interwoven, they enrich and strengthen the supervisory process by diversifying the supervisory dyad's ways of perceiving the unfolding therapeutic interaction and of coping with supervisory challenges.

Chirality-selective electromagnetically induced transparency in a dielectric metasurface based on chirality transfer between bright and dark modes

Chiral metasurfaces have wide applications in chiral sensing and functional devices, such as ultrathin circular polarizers. By analytical coupled mode theory and finite-difference time domain simulation, we investigate the chiroptical properties of designed dielectric metasurface with unit cell of corner-stacked nanorods and stacked nanorings, paying attention to the bright-dark-mode coupling effects. With the help of phase modulation and mode hybridization, we can realize chirality transfer from bright modes of chiral nanorods to dark modes of achiral nanorings, which results in chirality-selective transparency due to chirality-selective excitation of binding/antibonding dark modes. Moreover, one can switch between different coupling regimes with a distinct physical effect (Fano effect vs Rabi splitting) by changing only the chirality of the incident field without varying the structure of the metasurface. Based on the mechanisms of chirality transfer and mode hybridization, our designed metasurface has achieved chirality-selective transparent window with tunable central frequency and bandwidth, which provides insight and guidance for the optoelectronic device design.

Quantum networks assisted by dark modes in optomagnonic systems

Quantum networks assisted by dark modes in optomagnonic systems