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Photonic and Optoelectronic Devices and Systems, 4th Edition

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A special issue of Micromachines (ISSN 2072-666X). This special issue belongs to the section "A：Physics".

Deadline for manuscript submissions: 31 July 2026 | Viewed by 5269

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Dr. Muhammad Ali Butt

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Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, 00-662 Warsaw, Poland
Interests: integrated photonics; plasmonics; fiber-optic sensors; metasurfaces; wearable sensors
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Special Issue Information

Dear Colleagues,

Photonics refers to the study and application of the physical science of light. Photonic devices are components for creating, manipulating, or detecting light; examples include laser diodes, light-emitting diodes, switches, solar and photovoltaic cells, displays, and optical amplifiers. Moreover, optoelectronics is a rapidly developing technological discipline that involves the utilization of electronic devices to source, detect, and manipulate light. These devices can be used as a component of numerous applications, including automatic access control systems, telecommunications, and medical equipment. Since this discipline is so broad, the spectrum of devices that come under the field of optoelectronics is wide and includes image pick-up devices, LEDs and their elements, information displays, optical storage devices, remote sensing systems, and optical communication systems. In this Special Issue, reviews and novel research papers on this topic are welcome, as are interdisciplinary works.

Dr. Muhammad Ali Butt
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 250 words) can be sent to the Editorial Office for assessment.

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Keywords

optical waveguide devices
photonic sensors
photodiodes
solar cells
lasers
optical switches
logic gates
light-emitting diodes
plasmonics
metamaterials
photonic crystals
wearables
non-linear photonics
photonics for AI and neuromorphic computing
qauntum photonics

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Related Special Issues

Photonic and Optoelectronic Devices and Systems in Micromachines (9 articles)
Photonic and Optoelectronic Devices and Systems, Second Edition in Micromachines (13 articles)
Photonic and Optoelectronic Devices and Systems, Third Edition in Micromachines (11 articles)

Published Papers (9 papers)

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Research

Jump to: Review

12 pages, 1775 KB

Open AccessArticle

All-Optical Terahertz Dual-Band Logic Gates Based on Unidirectional Modes

by Dewang Guo, Yun You, Zhimin Liu and Jie Xu

Micromachines 2026, 17(5), 509; https://doi.org/10.3390/mi17050509 - 22 Apr 2026

Viewed by 192

Abstract

All-optical logic gates have emerged as a critical technology for enabling broadband, low-loss, and high-speed communication systems, addressing the inherent bandwidth limitations of electronic counterparts. Here, we propose a Y-shaped structure leveraging unidirectional modes in the terahertz regime, which enables the realization of multifunctional all-optical logic gates within the lower- and upper-frequency bandwidth regions, including, but not limited to, AND, OR, NOT, and XNOR gates. Numerical simulations and theoretical analyses confirm that the proposed logic gates exhibit robust one-way propagation characteristics, with electromagnetic signals demonstrating complete immunity to backscattering even in the presence of structural defects. Furthermore, nonlocal effects are found to have a negligible impact on the operational bandwidths of our design. Building upon this Y-shaped configuration, we further develop an all-optical digital logic system (AODLS) capable of supporting bifrequency multi-input and multi-output logic operations. When lower- and upper-frequency signals are injected into separate input ports, their corresponding output signals remain fully independent, eliminating cross-talk and enabling true parallel computation. This dual-band parallel processing capability represents a significant advance over conventional single-band all-optical logic systems, opening new avenues for high-throughput all-optical computing and integrated photonic circuits. Full article

(This article belongs to the Special Issue Photonic and Optoelectronic Devices and Systems, 4th Edition)

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11 pages, 3901 KB

Open AccessArticle

Polydimethylsiloxane-Based Quantum Dot Color Conversion Layers for QD-OLED Applications

by Sang-Uk Byun, Su-Been Lee, Seo-Young Kim, Yu-Lim Seok, Gun Park and Dae-Gyu Moon

Micromachines 2026, 17(5), 505; https://doi.org/10.3390/mi17050505 - 22 Apr 2026

Viewed by 254

Abstract

Quantum dot (QD)-based color conversion layers are key components in QD-OLED displays because they can provide high color purity and simplified pixel architectures by converting blue emission from OLEDs into red or green light. The performance of the color conversion layer strongly depends on the blue light absorption, blue leakage, and overall emission efficiency of the display. We fabricated the color conversion layers using a thermally curable polydimethylsiloxane (PDMS) matrix, and their color conversion characteristics were systematically compared with those of QD-only layers. In the QD-only layers, the intensity of the converted green emission increased with increasing QD concentration due to enhanced absorption of blue light emitted from the OLED. However, a large fraction of blue light was transmitted through the layer without being absorbed by the QDs, resulting in a significant blue leakage and a relatively low output/input efficiency below 10%. In contrast, PDMS-based QD color conversion layers exhibited substantially improved color conversion characteristics. By varying the QD concentration and controlling the layer thickness, blue leakage was significantly suppressed and the green emission intensity increased. The maximum color conversion efficiency of 30.0% was obtained at a QD concentration of 8.3 wt% with a layer thickness of 35.9 µm. Full article

(This article belongs to the Special Issue Photonic and Optoelectronic Devices and Systems, 4th Edition)

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11 pages, 6247 KB

Open AccessArticle

Design and Ultra-Precision Fabrication of Freeform Fresnel Lenses for Generating Rectangular Dark Hollow Beams

by Juan Zhang, Qilu Huang, Yingxin Xu, Chaocheng Yang and Tingdi Liao

Micromachines 2026, 17(4), 448; https://doi.org/10.3390/mi17040448 - 3 Apr 2026

Viewed by 368

Abstract

Freeform Fresnel lenses combine the powerful beam-shaping capability of freeform optics with the lightweight and compact characteristics of conventional Fresnel structures, leading to their increasing adoption across diverse applications. This paper proposes and experimentally validates a method for generating rectangular dark hollow beams using a freeform Fresnel lens. The lens is divided into multiple fan-shaped sectors centered on the optical axis, with each sector generating a defocused spot at a distinct spatial location. Based on geometrical optics, a freeform Fresnel lens with a 25 mm aperture is designed to produce a square hollow beam with a side length of 10 mm. A lens with a division angle of 5° was fabricated using ultra-precision diamond turning. The angular form error was measured to be below 0.1°, and the surface roughness was found to be below 10 nm. An optical testing system was established to characterize the generated beam profile. The experimental results successfully demonstrate the formation of the desired rectangular dark hollow beam. The measured results agree well with the simulations, confirming the feasibility and practical potential of the proposed method. Full article

(This article belongs to the Special Issue Photonic and Optoelectronic Devices and Systems, 4th Edition)

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19 pages, 4732 KB

Open AccessArticle

Triple-Cation Perovskite Photoanodes for Solar Water Splitting: From Photovoltaic-Assisted to Immersed Photoelectrochemical Operation

by Vera La Ferrara, Marco Martino, Antonio Marino, Giovanni Landi, Silvano Del Gobbo, Nicola Lisi, Rosanna Viscardi, Alberto Giaconia and Giulia Monteleone

Micromachines 2026, 17(4), 431; https://doi.org/10.3390/mi17040431 - 31 Mar 2026

Viewed by 424

Abstract

Mixed-halide perovskite solar cells with the composition Cs_0.1(MA_0.17FA_0.83)_0.9Pb(I_0.83Br_0.17)₃ were fabricated obtaining solar cells as glass/ITO/SnO₂/triple-cation perovskite/HTL/Au, and subsequently used as photoanodes for efficient solar-driven water splitting by attaching commercial catalytic nickel foils to the Au back-contact pads of solar cells. To enable operation in alkaline media, the devices were encapsulated using commercial PET–EVA multilayer films, providing an effective barrier while leaving the Ni foils exposed as the electrochemically active interface. Two operating configurations were investigated and compared: (i) an outside configuration, where the perovskite device powered the external electrochemical cell, and (ii) an immersed configuration, in which the encapsulated perovskite solar cell was directly integrated, together with the Ni catalyst, into the electrolyte. In both configurations, the onset potential for the oxygen evolution reaction shifted from ~1.32 V vs. RHE, when the Ni electrode was not powered by the perovskite solar cell, to ~0.34 V vs. RHE, when the perovskite device powered the Ni foil for both immersed and outside configurations. The immersed configuration delivered the highest performance, achieving a maximum Applied Bias Photon-to-Current Efficiency of ~20% under AM 1.5 G illumination (100 mW cm⁻²), among the highest values reported for perovskite-based photoanodes. Importantly, the enhanced performance does not arise from changes in catalyst composition or direct semiconductor–electrolyte interaction, but from improved photovoltage delivery and reduced resistive losses enabled by the integrated device architecture. These results demonstrate that device architecture is a key factor in controlling photovoltage utilization and charge-transfer kinetics, providing a viable strategy for efficient and scalable perovskite-based photoelectrochemical systems. Full article

(This article belongs to the Special Issue Photonic and Optoelectronic Devices and Systems, 4th Edition)

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18 pages, 4434 KB

Open AccessArticle

A Novel Spiral Si Drift Detector with a Constant Cathode Gap and Arbitrary Cathode Pitch Profiles

by Hongfei Wang and Zheng Li

Micromachines 2026, 17(3), 354; https://doi.org/10.3390/mi17030354 - 13 Mar 2026

Viewed by 305

Abstract

In this paper, an innovative design of a silicon spiral drift detector (SDD) has been proposed. In this design, gaps under the SiO₂ layer between the cathode rings are kept constant, with a minimum value to reduce the surface leakage current. The [...] Read more.

P (r)

as a function of radius

r

is allowed to change in an arbitrary way to achieve the optimum field distribution. The concept, design considerations, modeling and electrical simulations have been carried out for this novel structure with a hexagonal spiral silicon drift detector. Using one-dimensional analyses, we obtain the exact solution of the spiral design

r = r (θ)

with a near-arbitrary pitch profile

P (r) = P_{1} {(\frac{r}{r_{1}})}^{\frac{1}{η}}

, with

η

as an arbitrary real number. We also obtained the electric potential and field profiles on both surfaces of the detector. Using a Technology Computer-Aided Design (TCAD) tool, we made 3D simulations of the detector’s electrical properties. The hexagonal spiral silicon drift detector has excellent electrical properties: a uniform electric field, smooth distribution of electric potential and electron concentration, and a clear electron drift channel. The distributions of the electric field, electric potential, and electron concentration are symmetrical and smooth, which is beneficial for applications in photon sciences (X-ray) and safeguards and homeland security (particle radiation). The theoretical work and simulation results serve as solid foundations for the detector design and the expansion of semiconductor technology. Full article

(This article belongs to the Special Issue Photonic and Optoelectronic Devices and Systems, 4th Edition)

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10 pages, 2261 KB

Open AccessArticle

High-Extinction-Ratio Chiral Mid-Wave Infrared Photodetector Using Trapezoidal Si Pillars

by Yingsong Zheng, Longfeng Lv, Yuxiao Zou, Bo Cheng, Hanxiao Shao, Guofeng Song and Kunpeng Zhai

Micromachines 2026, 17(2), 181; https://doi.org/10.3390/mi17020181 - 28 Jan 2026

Viewed by 453

Abstract

Although the polarization state, as a key physical dimension of light, plays an irreplaceable role in many frontier fields such as quantum communication and chiral sensing, traditional photodetectors are limited by the inherent optical isotropy of materials and thus are unable to directly distinguish circular polarization information. This paper numerically reports a miniature circular polarization photodetector based on chiral metasurfaces, which achieves an excellent extinction ratio of up to 31 dB through the collaborative regulation of geometric displacement manipulation and tilt angle operation. This device utilizes the symmetry-breaking effect to construct significantly different transmission spectral responses between left circularly polarized light (LCP) and right circularly polarized light (RCP). Our research not only provides a high-performance implementation solution for on-chip polarization detection but also opens up new paths for the future development of quantum optics, integrated sensing, and ultra-compact polarization optical systems. Full article

(This article belongs to the Special Issue Photonic and Optoelectronic Devices and Systems, 4th Edition)

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10 pages, 3414 KB

Open AccessArticle

PN Tandem Solar Cells Based on Combination of Dye-Sensitized TiO₂ Photoanode and Perovskite-Sensitized NiO Photocathode

by Huan Wang, Weicheng Tang, Mengru Li and Xiaoli Mao

Micromachines 2026, 17(1), 99; https://doi.org/10.3390/mi17010099 - 12 Jan 2026

Cited by 1 | Viewed by 585

Abstract

Dye-sensitized solar cells (DSSCs) have attracted significant attention as next-generation photovoltaic devices due to their low cost, simple fabrication process, use of earth-abundant materials, and potential for colour tunability and transparency. p–n tandem DSSCs have garnered particular interest owing to their higher open-circuit voltage compared to single-junction DSSCs. However, the performance of such tandem devices remains limited by relatively low open-circuit voltage and short-circuit current density, primarily due to the scarcity of suitable p-type sensitizers. To address this challenge, we report a novel p–n tandem solar cell integrating a dye-sensitized TiO₂ photoanode with a perovskite-sensitized NiO photocathode, achieving a record power conversion efficiency of 4.02%. By optimizing the thickness of the TiO₂ layer, a maximum open-circuit voltage of 1060 mV and a peak short-circuit current density of 6.11 mA cm⁻² were simultaneously attained. Full article

(This article belongs to the Special Issue Photonic and Optoelectronic Devices and Systems, 4th Edition)

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13 pages, 2143 KB

Open AccessArticle

O-Band 4 × 1 Combiner Based on Silicon MMI Cascaded Tree Configuration

by Saveli Shaul Smolanski and Dror Malka

Micromachines 2026, 17(1), 31; https://doi.org/10.3390/mi17010031 - 26 Dec 2025

Cited by 1 | Viewed by 800

Abstract

High-speed silicon (Si) photonic transmitters operating in the O-band require higher on-chip optical power to support advanced modulation formats and ever-increasing line rates. A straightforward approach is to operate laser diodes at higher output power or employ more specialized sources, but this raises cost and exacerbates nonlinear effects such as self-phase modulation, two-photon absorption, and free-carrier generation in high-index-contrast Si waveguides. This paper proposes a low-cost 4 × 1 tree-cascade multimode interference (MMI) power combiner on a Si-on-insulator platform at 1310 nm wavelength that enables coherent power scaling while remaining fully compatible with standard commercial O-band lasers. The device employs adiabatic tapers and low-loss S-bends to ensure uniform field evolution, suppress local field enhancement, and mitigate nonlinear phase accumulation. The optimized layout occupies a compact footprint of 12 µm × 772 µm and achieves a simulated normalized power transmission of 0.975 with an insertion loss of 0.1 dB. Spectral analysis shows a 3 dB bandwidth of 15.8 nm around 1310 nm, across the O-band operating window. Thermal analysis shows that wavelength drift associated with ±50 °C temperature variation remains within the device bandwidth, ensuring stable operation under realistic laser self-heating and environmental changes. Owing to its broadband response, fabrication tolerance, and compatibility with off-the-shelf laser diodes, the proposed combiner is a promising building block for O-band transmitters and photonic neural-network architectures based on cascaded splitter and combiner meshes, while preserving linear transmission and enabling dense, large-scale photonic integration. Full article

(This article belongs to the Special Issue Photonic and Optoelectronic Devices and Systems, 4th Edition)

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Review

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32 pages, 8754 KB

Open AccessReview

Plasmonics Meets Metasurfaces: A Vision for Next Generation Planar Optical Systems

by Muhammad A. Butt

Micromachines 2026, 17(1), 119; https://doi.org/10.3390/mi17010119 - 16 Jan 2026

Cited by 2 | Viewed by 1309

Abstract

Plasmonics and metasurfaces (MSs) have emerged as two of the most influential platforms for manipulating light at the nanoscale, each offering complementary strengths that challenge the limits of conventional optical design. Plasmonics enables extreme subwavelength field confinement, ultrafast light–matter interaction, and strong optical nonlinearities, while MSs provide versatile and compact control over phase, amplitude, polarization, and dispersion through planar, nanostructured interfaces. Recent advances in materials, nanofabrication, and device engineering are increasingly enabling these technologies to be combined within unified planar and hybrid optical platforms. This review surveys the physical principles, material strategies, and device architectures that underpin plasmonic, MS, and hybrid plasmonic–dielectric systems, with an emphasis on interface-mediated optical functionality rather than long-range guided-wave propagation. Key developments in modulators, detectors, nanolasers, metalenses, beam steering devices, and programmable optical surfaces are discussed, highlighting how hybrid designs can leverage strong field localization alongside low-loss wavefront control. System-level challenges including optical loss, thermal management, dispersion engineering, and large-area fabrication are critically examined. Looking forward, plasmonic and MS technologies are poised to define a new generation of flat, multifunctional, and programmable optical systems. Applications spanning imaging, sensing, communications, augmented and virtual reality, and optical information processing illustrate the transformative potential of these platforms. By consolidating recent progress and outlining future directions, this review provides a coherent perspective on how plasmonics and MSs are reshaping the design space of next-generation planar optical hardware. Full article

(This article belongs to the Special Issue Photonic and Optoelectronic Devices and Systems, 4th Edition)

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