Reflective Mirror Research Articles

Direct 3D-printed ring-resonator photonic circuit on a dual core fiber tip for remote sensing applications.

On-chip optical sensors using ring- and disk-resonators have many potential sensing applications, yet robust and efficient fiber-to-chip coupling and the differing form factor between the two pose deployment challenges. To resolve this, we 3D-printed a ring-resonator onto the tip of a dual-core fiber and demonstrate its use as a remote temperature sensor. The fiber-tip optical circuit is fabricated using direct laser writing (DLW) with two-photon absorption photopolymer material IP-Dip, forming micrometer-scale waveguide cores having a refractive index of 1.53 with a surrounding air cladding. We connect the two-fiber cores by a printed bus-waveguide, utilizing total internal reflection mirrors, allowing light launched into one core to be guided back to the other core. Furthermore, a DLW printed racetrack resonator evanescently coupled to the bus waveguide (Q ∼ 3000) imposes spectral dips on resonance wavelengths. Light sent down into one core is interrogated upon return from the second core, all from the distal end of the sensor. When the sensing end's temperature is varied, we find a sensitivity of 78 pm/K, due to the polymer's thermo-optic index variation. The ring-resonator could be functionalized for other sensing applications.

Optical Thin Films in Space Environment: Investigation of Proton Irradiation Damage.

The present work reports a systematic study of the potential degradation of metals and dielectric thin films in different space environments. The mono- and bilayers selected are made of materials commonly used for the realization of optical components, such as reflective mirrors or building blocks of interferential filters. More than 400 samples were fabricated and irradiated with protons at different energies on ground-based facilities. The fluences were selected as a result of simulations of the doses delivered within a long-term space mission considering different orbits (Sun close, Jovian, and Geostationary orbits). In order to stress the samples at different depths and layer interfaces, experiments were carried out with a range of proton energies within 1 and 10 MeV values. An estimate of a safe maximum fluence has been provided for each type of sample at each energy. The damage mechanism, when present, has been investigated with different optical and structural techniques.

Particle-in-cell simulations of EUV-induced hydrogen plasma in the vicinity of a reflective mirror

Particle-In-Cell (PIC) simulations were performed in this work to study the dynamics of the EUV-induced hydrogen plasma. The Monte-Carlo Collision (MCC) model was employed to deal with the collisions between charged particles and background gas molecules. The dynamic evolution of the plasma sheath, as well as the flux and energy distribution of ions impacting on the mirror surface, was discussed. It was found that the emission of secondary electrons under the EUV irradiation on the ruthenium mirror coating creates a positively charged wall and then prevents the ions from impacting on the mirror and therefore changes the flux and energy distribution of ions reaching the mirror. Furthermore, gas pressure has a notable effect on the plasma sheath and the characteristics of the ions impinging on the mirrors. With greater gas pressure, the sheath potential decreases more rapidly. The flux of ions received by the mirror grows approximately linearly and at the same time the energy corresponding to the peak flux decreases slightly. However, the EUV source intensity barely changes the sheath potential, and its influence on the ion impact is mainly limited to the approximate linear increase in ion flux.

Calculation model of rectangular-like Herriott cell based on folded-optics method

We present a calculation model for rectangular-like Herriott cells (RLHCs), in which a long cylindrical traditional Herriott cell (HC) is transformed into a rectangular-like configuration by introducing two highly reflective plane mirrors. The position formula for two spheric mirrors and two plane mirrors is provided to precisely define the RLHC. The folding effects of RLHCs with 1–8-times folding are evaluated in terms of the cell length, the cell volume, and the total number of reflections. The proposed folded-optics method significantly enhances the utilization efficiency of the mirror surfaces, resulting in a reduction of both physical length and volume when compared to a traditional HC. Importantly, this reduction is achieved while maintaining the same optical path length, and all of these advantages come at a low cost.

Wong Kar-wai’s Argentine Affair: Happy Together as a Translingual and Multimodal Adaptation

Abstract In 2021, a 4K-restored rendition of Wong Kar-wai’s iconic film Happy Together (1997) returned to theatres across Hong Kong, Taiwan, and Argentina, marking the film’s enduring transnational appeal two decades after its Cannes premiere. This article investigates the film’s intricate cultural ties to Argentina. I argue that Happy Together not only enhances the cultural connections between Hong Kong and Argentina but also showcases Wong’s translingual and multimodal approaches to film adaptation. ‘Translingual’ refers to the film’s literary source: I demonstrate how Wong skilfully wove elements from Manuel Puig's 1973 novel The Buenos Aires Affair into his film through a threefold Spanish-English-Chinese process of rewriting. Subsequently, I contend that various cultural facets of Argentina—the literature of Puig, the soundscape of Piazzolla’s tango, and the landscapes of the Iguazú Falls and Tierra del Fuego—contributed significantly to the Hong Kong auteur’s multimodal adaptation. In short, this article proposes a dialogic perspective on Hong Kong cinema by considering Argentina as a reflective mirror brimming with aesthetic and geopolitical implications. Through the lens of Happy Together, this study moves beyond Western-centric reception paradigms by spotlighting the cultural and socio-political affinities between Latin America and Asia, thus bringing to the forefront the often-overlooked transpacific connections within the Global South.

Laser welding by focusing multi-laser beams

This paper presents a multi-laser beam focusing on laser welding based on a reflective splitting mirror, aiming to improve the stability of the laser welding process and reduce welding defects. By validating the laser welding process on Q235 mild steel using a newly developed multi-focused laser beam, the results show that by increasing the number of laser focal points, the porosity and spattering are effectively reduced, thus achieving higher process stability. Additionally, the rotation of the laser focal point further reduces the occurrence of welding defects such as porosity and spattering.

Highly efficient nonlinear compression of mJ pulses at 2 μm wavelength to 20 fs in a gas-filled multi-pass cell

Within this work we demonstrate the highly efficient nonlinear spectral broadening and subsequent temporal compression of 1.49 mJ pulses at 101 kHz repetition rate from an ultrafast thulium-doped fiber laser system employing a gas-filled multi-pass cell (MPC). To achieve spectral broadening, we use a krypton and helium-filled Herriott-type MPC with highly reflective broadband dielectric mirrors. The spectrally broadened pulses are subsequently compressed using fused-silica plates, resulting in a pulse duration of 20 fs and an overall excellent transmission of 96%. Furthermore, the beam quality is preserved up to the maximum output power of 144 W. It provides, to the best of our knowledge, the highest average power with few-cycle pulses at 2 µm wavelength with almost 10 times more pulse energy and 3 times more average power than previous 2 µm MPCs, enabling future secondary source experiments.

Optimal design and analysis of a space lightweight mirror with a directionally oriented 2.5D-CVT structure

Reflective mirrors are the key imaging components of space-borne telescopes, which require a high lightweight ratio integrated with excellent optical properties. In this context, a novel, to our knowledge, 2.5D centroidal Voronoi tessellation (CVT) generation methodology is proposed for designing and optimizing a lightweight mirror structure. Firstly, the initial designs are obtained combining global sensitivity factor mapping and local distribution optimization. Then, the optimal model is selected through multi-objective optimization and decision making. Subsequently, the FEA (finite element analysis) results indicate that, under the same mass, the proposed design exhibits better optomechanical performance. Finally, in practical applications, the approach presented in this paper outperforms the traditional design for each technological requirement, including a 62% reduction in RMS and a higher lightweight ratio. This method offers a kind of novel design and optimization process for space-based optomechanical lightweight structures.

Experimental investigation of a sun tracking concentrated solar still with economic analysis

The current paper evaluated experimentally an innovative sun tracking concentrated solar still under Egyptian climatic conditions during the summer of 2022. The proposed system consists of a 120-cm-diameter parabolic reflector mirror that tracks the sun using a dual axis tracking system, a cylindrical solar still with a volume of 3.7 L positioned in its focal point, and a concentration ratio of 12.5. The performance of the concentrated solar still was investigated in the context of two critical parameters. First, three feed water salinity (17, 27, 37) ppt samples were evaluated, followed by four percentages of saline water filling ratio (26.5, 39.8, 53.1, 66.3)%. Increasing the salinity of the feed water had no effect on solar still productivity, but increasing the saline water filling ratio did. The daily cumulative productivity of the system was 6 kg/m2 with an optimal filling ratio of 53.1%, a daily efficiency of 42.88%, and an average cost of freshwater production of 0.0489 $/L. The proposed system also had the highest instantaneous efficiency of 61.77% and the highest distilled water productivity rate of 0.941 kg/h m2.

Bi-functional dynamic tunable absorber and highly robust polarisation converter for graphene-based metasurface

In this study, a graphene-based metasurface structure with bi-functional dynamically tunable absorber and highly robust polarisation converter is proposed. The device primarily consists of two functional tiers. The top tier of cyclically patterned graphene and the back of a fully reflective gold mirror, which are separated by an intermediate tier of SiO2 dielectric to form a typical sandwich structure. The proposed device is numerically calculated by finite element method (FEM), and the equivalent R-L-C circuit model is built to validate the calculated results. The proposed reflective-type circularly to circularly polarisation converter (RCCPC) has a wide operating band of 0.8 THz (2.12 THz to 2.92 THz) and can obtain near unity polarisation conversion rate (χPCR). It is worth noting that the device is also immune to structural parameter deviations. In addition, due to the excited charge of monolayer graphene has the cyclotron property in a static magnetic field, the cross-polarised component of the polarisation converter can be increased by applying a vertical magnetic field, which provides a feasible method to improve the energy conversion rate of the device. At the same time, the device can also serve as a narrowband dual channel absorber, with 95 % absorption effect. In addition, the tunability of graphene is based on the correlation between conductivity and Fermi energy. As the Fermi energy changes, the working frequency of the device is shifted, realizing the dynamic tunable absorber and polarisation converter. It is believed that these findings provide a way to implement a variety of novel multifunctional photonic device, including polarisation imaging, electromagnetic energy absorption, and integrated photonic devices.

Detection of Volatile Organic Compounds through Spectroscopic Signatures in Nanoporous Fabry-Pérot Optical Microcavities.

Increasingly complex modern gas-monitoring scenarios necessitate advanced sensing capabilities to detect and identify a diverse range of gases under varying conditions. There is a rising demand for individual sensors with multiple responses capable of recognizing gases, identifying components in mixtures, and providing stable responses. Inspired by gas sensors employing multivariable response principles, we develop a nanoporous anodic alumina high-order microcavity (NAA-HOμCV) gas sensor with multiple optical outputs for discriminative gas detection. The NAA-HOμCV architecture, formed by a Fabry-Pérot microcavity with distributed Bragg reflector (DBR) mirrors and an extended-length microcavity layer supporting multiple resonant modes, serves as an effective solid-state fingerprint platform for distinguishing volatile organic compound (VOC) gases. Our research reveals that the coupling strength of light into resonant modes and their evolution depend on the thickness of the DBR mirrors and the dimension of the microcavity layer, which allows us to optimize the discriminative sensing capability of the NAA-HOμCV sensor through structural engineering of the microcavity and photonic crystal mirrors. Gas-sensing experiments conducted on the NAA-HOμCV sensor demonstrate real-time discrimination between physiosorbed VOC gases (isopropanol, ethanol, or acetone) in reversible gas sensing. It also achieves superior ppb-level sensing in irreversible gas sensing of model silane molecules. Our study presents promising avenues for designing compact, cost-effective, and highly efficient gas sensors with tailored properties for discriminative gas detection.

Observation or Insight? Unraveling the Impact of Characters' Image on Interpersonal Communication in Contemporary Chinese TV Series

A salient determinant of effective interpersonal communication resides in the cultivation of a positive personal image. The intricate interplay between self-image, individual behaviors, and communication abilities highlights the far-reaching influence of personal perception on social interactions. In the contemporary landscape of Chinese television series, exemplified by the production ‘Nothing but Thirty’, a deliberate effort is made to depict characters that embody the evolving roles of women in modern society. Drawing from relevant literature, this study conducts a comprehensive analysis of characters’ image in ‘Nothing but Thirty’, examining content such as appearance, language, non-verbal cues (body language), and varied scene settings. Adopting a rigorous qualitative case study methodology and leveraging content analysis grounded in the coordinated management of meaning theory and social exchange theory, the research aims to dissect the nuanced dynamics of interpersonal communication as portrayed in the series. The findings illuminate that the dynamic characterizations in contemporary Chinese TV series function as reflective mirrors, capturing the intricate layers of modern interpersonal communication and societal intricacies. This narrative analysis extends beyond the purview of conventional storytelling, offering a scholarly exploration of the intricate fabric of human interaction.

Multiple adaptive factors based interacting multiple model estimator

AbstractIn the field of optoelectronic tracking, precisely modeling the motion equations of the tracked target is often challenging, and in some cases, they may even be entirely unknown. This necessitates the use of a robust state estimator for accurate state estimation. Additionally, atmospheric turbulence, variations in illumination, and intricate observation backgrounds may introduce a significant increase in observation noise for the tracked target. To address these challenges, one approach is to introduce adaptive factors, such as the Mahalanobis method, into the robust state estimator to enhance estimation accuracy. However, further exploration has revealed that adaptive factors designed using different methods offer unique advantages in scenarios with varying levels of noise amplification. In this paper, different adaptive factors are further combined using an interacting multiple model approach, allowing the designed state estimator to exhibit stronger adaptability to noise amplification. The stability and effectiveness of this algorithm are validated through program simulations, double reflection mirror experiment, and drone trace prediction, demonstrating its applicability and reliability in diverse scenarios.

Observation of dynamic nanoscale thermal expansion in mirrors and graphene-aided heat dissipation by an advanced chromatic confocal microscopy

In this Letter, dynamic nano-thermal expansion images of reflective mirrors from high-intensity incident laser beams were observed in situ. The inspections are based on rapid 3D surface morphology changes on the reflective surfaces, captured by a Chromatic Confocal Microscope with Nanoscale Sensitivity (CCMNS). Nano-expansions of two types of coatings were studied: the E02 dielectric coating (coating 1) and the graphene-on-E02 complex film (coating 2), both applied to the same fused silica substrate. The superior thermal dissipation properties of coating 2, including enhanced heat dissipation, suppressed wavefront distortion, and its unique negative expansion coefficient, were observed. In addition to studying the effects of graphene coating, the CCMNS demonstrates an accurate and efficient approach for evaluating reflective mirrors. Moreover, the proposed methodology possesses enormous potential across various fields, ranging from estimating photonic elements dealing with high-intensity beams to physical thermal conductivity measurements.

Angular‐Dispersive Narrowband Absorption Induced by Quasi‐BIC in SiO2‐Au Metamaterial

Quasibound states in the continuum (BIC) have earned extensive attentions due to the capability to realize extremely high quality‐factor (Q‐factor) resonance. Here, a metamaterial composed of silicon dioxide (SiO2) with low refractive index (≈1.45) on gold (Au) reflection mirror is proposed to realize narrowband perfect absorption with the assistance of quasi‐BIC and surface lattice resonance. The proposed SiO2‐Au absorber based on SiO2 metamaterial is composed of two tilted SiO2 cubes into a unit cell and periodically arranged on Au reflection mirror. By optimizing the geometry parameters, the proposed absorber presents both accidental quasi‐BIC and symmetry‐protected quasi‐BIC modes with near‐perfect absorptivity and high Q‐factor of 2330 and 1438, respectively. The Q‐factor can be further improved to 104 by increasing the thickness of SiO2 cubes to micrometer level. Meanwhile, the wavelength of absorption peak shows linear sensitivity of 16.67 and 17.88 nm per degree to incident angles as the absorptivity is higher than 92% and 75% in the spectra range of 215.0–141.0 nm, respectively. These results open the avenue for the metamaterial absorber in emitter, imaging, and biosensing applications.

Design of a dual hollow beam optical antenna based on a Fresnel lens-conical lens combination

To improve the transmission efficiency of Cassegrain antennas and enable the simultaneous transmission of signals with different wavelengths in the antenna system, this study introduces Fresnel lenses and conical lenses in front of the Cassegrain antenna at the transmitting end. Reflective mirrors and focusing lenses are introduced at the receiving end. A detailed description is provided of the design process for the Fresnel lens, as well as the impact of various parameters on the hollow radius when combined with the conical lens. Based on the laws of vector reflection and refraction, simulations are performed to track the propagation of light through the entire communication system and lens pairs, providing transmission efficiency plots of the antenna system under deflection and off-axis conditions. Taking into account practical factors such as lens chamfer, transmittance, Cassegrain antenna reflectance, and material dispersion, the transmission efficiency of the antenna system at 1550 nm wavelength can still reach 93.45%. The proposed method not only improves the transmission efficiency of Cassegrain antennas, but also enables the transmission of different information through the inner and outer layers of the antenna system.

Temperature dependence of refractive indices of InP , GaAs , AlAs , and In0.53Ga0.47As in the midinfrared spectral range determined by combined ellipsometry and Fourier-transform spectroscopy

We present the results of Fourier-transform measurements for determination of refractive indices of four semiconductor alloys in the midinfrared spectral range from 10 to 300 K. We investigate double-sided-polished, undoped InP and GaAs substrates as well as In0.53Ga0.47As/InP and AlAs/GaAs distributed Bragg reflector (DBR) mirrors with their operational wavelength designed for 4 µm. Through analysis of measured transmittance spectra supported by ellipsometry it is possible to determine the temperature-dependent refractive indices of InP and GaAs from 1.3 to 11 µm. Furthermore, by using reflectivity measurements supported by numerical modeling of the two types of designed DBR structures the refractive indices of In0.53Ga0.47As and AlAs for around 4 µm are determined with their temperature dependencies. Data acquired through this method could lead to improvement of already existing optical semiconductor devices expanding their application for longer wavelengths. Published by the American Physical Society 2024

Ultrahigh-reflective optical thin films prepared by reactive magnetron sputtering with RF-induced substrate bias.

Optical thin films with high-reflectivity (HR) are essential for applications in quantum precision measurements. In this work, we propose a coating technique based on reactive magnetron sputtering with RF-induced substrate bias to fabricate HR-optical thin films. First, atomically flat SiO2 and Ta2O5 layers have been demonstrated due to the assistance of radio-frequency plasma during the coating process. Second, a distributed Bragg reflector (DBR) mirror with an HR of ∼99.999 328% centered at 1397nm has been realized. The DBR structure is air-H{LH}19-substrate, in which the L and H denote a single layer of SiO2 with a thickness of 237.8nm and a single layer of Ta2O5 with a thickness of 171.6nm, respectively. This novel coating method would facilitate the development of HR reflectors and promote their wide applications in precision measurements.

The importance of communication through social media in building clients satisfaction for hotel institutions

Purpose. This study aims to understand how to build a positive relationship between communication via social media and customer satisfaction for classified hotel establishments, with a particular focus on the Marriott International hotel chain. It explores the importance of extracting and analyzing the opinions of customers of the Marriott International hotel chain on social media platforms, identifying the most common positive and negative aspects in the evaluations of the mentioned hotel series. Results. The results indicate that communication via social media has a positive impact on customer satisfaction, which in turn affects the performance of hotel establishments. Additionally, active interaction with customers and monitoring their electronic reviews on social media platforms assists in identifying areas for improvement and contributes to enhancing the hotel’s reputation, offering insights for hotel managers to improve customer service strategies. Scientific novelty. To the best of the researchers’ knowledge and based on their review, the current study presents its novelty by encompassing all the hotels of the Marriott International chain for the year 2023. It demonstrates that most social media platforms utilized by these entities were explored, and user opinions were extracted and analyzed using tools such as Excel 2022 and Google Analytics. Additionally, the study incorporates the Uses and Gratifications Theory. It contributes to the existing literature by providing insights into how to effectively leverage social media to enhance customer experiences in the hospitality sector. Practical value. The practical value of the study lies in highlighting the importance of utilizing and analyzing user reviews and ensuring the effective use of social media, as it serves as a reflective mirror for hotels. It has the potential to direct businesses in the hospitality sector to improve interactions with clients and increase satisfaction, as observed with the Marriott International hotel chain.

A spectral splitting CPV/T hybrid system based on wave-selecting filter coated compound parabolic concentrator and linear Fresnel reflector concentrator

Efficient full-spectrum solar energy utilization shows great potential to improve solar energy conversion efficiency. In this paper, a spectral splitting concentrated photovoltaic/thermal hybrid system based on a wave-selecting filter-coated compound parabolic concentrator and linear Fresnel reflector mirror field is developed. Optical models to simulate the linear Fresnel reflector have been developed and validated. With the wave-selecting filter coated compound parabolic concentrator, the visible and near infrared spectra transmit onto the photovoltaic cells, while the rest are reflected to the receiver tube. Furthermore, a simplified receiver indoor test prototype is designed to investigate the characteristic of solar photovoltaic module with the spectral filter in the context of the compound parabolic concentrator. The measured I–V curves are compared with the modeled results. Additionally, the thermodynamic performance of the system is analyzed. Parametric studies are performed to investigate the effect of key design parameters including the mirror width, focal length and the radius of the receiver tube on the solar flux density and the exergy efficiency. An exergy efficiency of 35.51% and an optical efficiency of 94.78% are achieved. With a preliminary techno-economic analysis, the levelized cost of the electricity of the system is $0.209/kWh with a payback period of 10 years.