Hasil untuk "Applied optics. Photonics"

Sareh Vatani, Vahid Faramarzi, Jeongwon Park

This paper details the design and theoretical analysis of a novel thermo-optical modulator that leverages the unique phase transition characteristics of vanadium dioxide (VO₂) and the plasmonic properties of graphene. Employing a combination of transmission and reflection mode structures, the study explores four configurations designed to optimize modulation depth and minimize insertion loss. The analysis conducted using COMSOL Multiphysics with the finite element method (FEM) highlights the significant influence of geometrical parameters on the modulator’s performance. The specific attention to the interaction between VO₂’s phase transition at critical temperatures and graphene’s conductivity adjustment provides insights into the dynamic control of optical signals in the mid-infrared spectrum.

Youngin Kim, Laurenz Kulmer, Jae-Yong Kim et al.

We demonstrate an electronic-photonic (EP) interface for multiuser optical wireless communication (OWC), consisting of a multibeam optical phased array (MBOPA) along with co-integrated electro-optic (EO) modulators and high-speed CMOS drivers. The MBOPA leverages a path-length difference in the optical phased array (OPA) along with wavelength-division multiplexing technology for spatial carrier aggregation and multiplexing. To generate two and four pulsed amplitude modulation signals, and transmit them to multiple users, we employ an optical digital-to-analog converter technique by using two traveling-wave electrode Mach-Zehnder modulators, which are monolithically integrated with high-speed, wide-output-swing CMOS drivers. The MBOPA and monolithic EO modulator are implemented by silica wafer through planar lightwave circuit fabrication process and a 45-nm monolithic silicon photonics technology, respectively. We measured and analyzed two-channel parallel communication at a data rate of 54 Gbps per user over the wireless distance of 1 m. To the best of our knowledge, this is the first system level demonstration of the multi-user OWC using the in-house-designed photonic and monolithically integrated chips. Finally, we suggest best modulation format for different data rate and the number of multibeams, considering effects of the proposed OPA and the monolithic modulator.

Zhen Wang, Qinxue Nie, Haojia Sun et al.

Abstract Photoacoustic dual-comb spectroscopy (DCS), converting spectral information in the optical frequency domain to the audio frequency domain via multi-heterodyne beating, enables background-free spectral measurements with high resolution and broad bandwidth. However, the detection sensitivity remains limited due to the low power of individual comb lines and the lack of broadband acoustic resonators. Here, we develop cavity-enhanced photoacoustic DCS, which overcomes these limitations by using a high-finesse optical cavity for the power amplification of dual-frequency combs and a broadband acoustic resonator with a flat-top frequency response. We demonstrate high-resolution spectroscopic measurements of trace amounts of C2H2, NH3 and CO in the entire telecommunications C-band. The method shows a minimum detection limit of 0.6 ppb C2H2 at the measurement time of 100 s, corresponding to the noise equivalent absorption coefficient of 7 × 10−10 cm−1. The proposed cavity-enhanced photoacoustic DCS may open new avenues for ultrasensitive, high-resolution, and multi-species gas detection with widespread applications.

R. Middleton, M. Sinnott-Armstrong

This Tutorial introduces structural color in fruits as a phenomenon of diverse optical materials. Originally best known in abiotic materials and animals, structural colors are being increasingly described in plants. Structural colors have already inspired a variety of useful products, and plants are especially attractive as models to develop new bioinspired technologies thanks to the comparative ease of working with them compared with animal systems. Already, human-engineered structural colors modeled after plant cellulose-based architectures have shown promising applications in colorants and sensors. However, structural colors include a far broader group of materials and architectures beyond cellulose. Understanding the new and diverse structures that have recently been described in plants should provoke research into new bioinspired products based on plant optical structures and biomaterials. In this Tutorial, we focus on fruits as new structures have recently been discovered, leading to new opportunities for bioinspired technologies. We bring together a review of optical structures found in fruits from a physical optics perspective, with a consideration of each structure as an opportunity in bioinspired and biomimetic design.

Hongyu Song, Haoyu Wu, Yanpei Xu et al.

Abstract Glucose is an indispensable nutrient for metabolism in living organisms and is widely used in food, industry, and medical fields. Glucose is often added as a sweetener in food and often used in industry as a reducing agent for various products. In medical treatment, glucose is added to many drugs as a nutritional additive, and it is also an indicator that diabetics need to pay attention to at all time. Therefore, the market has a great demand for low-cost, high-sensitivity, fast, and convenient glucose sensors, and the industry has always attached great importance to the work of creating new glucose sensor devices. Therefore, we proposed a SnO2 nanofibers/Au structure multimode-single-mode-multimode (MSM) fiber surface plasmon resonance (SPR) glucose sensor. SnO2 nanofibers were fixed to a single-mode fiber core that had been plated with the Au film by electrospinning. When the glucose concentration increased at 5 vol% intervals, the corresponding resonance wavelengths had different degrees of redshifts. Comparing the two structures, as the glucose concentration range increased from 0 vol% to 60 vol%, the sensitivity increased from 228.7 nm/vol% in the Au structure to 337.3 nm/vol% in the SnO2 nanofiber/Au structure. At the same time, the linear correlation between the resonant wavelength and the refractive index of the two structures was greater than 0.98. Moreover, the SnO2 nanofibers/Au structure significantly improved the practical application performance of SPR sensors.

G. Perda, L. Morelli, L. Morelli et al.

In industrial vision metrology, precise spatial measurement is vital for quality control and complex manufacturing, traditionally relying on target arrays for sub-pixel accuracy (0.05–0.1 pixels) and precision to beyond 1:200,000. However, target design, placement and measurement are often time-consuming and challenging for large-scale projects. Automated, markerless methods, generally called Structure-from-Motion (SfM), based on handcrafted algorithms or deep learning-based pipelines, offer greater flexibility but are not widely adopted due not only to concerns about reliability and precision, but also because in many industrial photogrammetry applications targets highlight particular feature points of interest, e.g. tooling points, holes and edges. This study reviews the differences between target-, handcrafted- and learning-based approaches, explores hybrid methods combining targets and natural features, and tests learning-based or handcrafted approaches against the traditional target-based method. Two end-to-end learning-based pipelines based on SuperPoint+LightGlue and KeyNet+AffNet+HardNet are evaluated. Results show that deep learning pipelines for tie point extraction provide enhanced automation but inferior triangulation precision, while being comparable to handcrafted methods.

Keisuke Kawahara, Toshihiko Baba

The increasing demand for high-speed optical interconnects necessitates integrated photonic and electronic solutions. Electro-optic co-simulation is key to meeting these requirements, which works by importing interoperable photonic models into industry-standard electronic circuit simulators from Synopsys, Cadence, Keysight, and others. However, current interoperable photonic models cannot accurately predict performance and do not address terabit-class transceiver designs due to inadequate modeling of complex physical effects such as optical losses, back-reflection, nonlinearity, high-frequency response, noise, and manufacturing variations. Here, we present accurate and interoperable photonic models that agree well with experiments at symbol rates exceeding 50 Gbaud. The developed models include basic optical components with losses and reflections, two types of Mach-Zehnder modulators with validated high-frequency response, and testing equipment with associated noise. We built an optical link testbench on an industry-standard electronic circuit simulator and verified the model accuracy by comparing simulation and experiment up to 64 Gbaud. The results suggest that co-simulation will be a solid basis for advancing design of transceivers and other related applications in silicon photonics.

Yiwen Zhang, Jingwei Yang, Zhaoxi Chen et al.

The terahertz (THz) frequency range, bridging the gap between microwave and infrared frequencies, presents unparalleled opportunities for advanced imaging, sensing, communications, and spectroscopy applications. Terahertz photonics, in analogy with microwave photonics, is a promising solution to address the critical challenges in THz technologies through optical methods. Despite its vast potential, key technical challenges remain in effectively interfacing THz signals with the optical domain, especially THz-optic modulation and optical generation of THz waves. Here, we address these challenges using a monolithic integrated photonic chip designed to support efficient bidirectional interaction between THz and optical waves. Leveraging the significant second-order optical nonlinearity and strong optical and THz confinement in a thin-film lithium niobate on quartz platform, the chip supports both efficient THz-optic modulation and continuous THz wave generation at up to 500 GHz. The THz-optic modulator features a radio frequency (RF) half-wave voltage of 8V at 500 GHz, representing more than an order of magnitude reduction in modulation power consumption from previous works. The measured continuous wave THz generation efficiency of 4.8*10-6 /W at 500 GHz also marks a tenfold improvement over existing tunable THz generation devices based on lithium niobate. We further leverage the coherent nature of the optical THz generation process and mature optical modulation techniques to realize high-speed electro-THz modulation at frequencies up to 35 GHz. The chip-scale THz-photonic platform paves the way for more compact, efficient, and cost-effective THz systems with potential applications in THz communications, remote sensing, and spectroscopy.

Masoud Shabaninezhad, Hamid Mehrvar, Eric Bernier et al.

We present the design, modeling, and optimization of high-performance plasmonic electro-optic modulators leveraging voltage-gated carrier density in indium tin oxide (ITO) where the gated carrier density is modeled using both the Classical Drift-Diffusion (CDD) and Schrödinger-Poisson Coupling (SPC) methods. The latter ensures a more detailed and precise description of carrier distributions under various gate voltages which gains particular significance when applied to an epsilon-near-zero (ENZ) medium such as ITO. Combining the nanoscale confinement and field enhancement enabled by surface plasmon polaritons with the ENZ effect in ITO, modulator designs integrated with silicon waveguides and optimized for operation at λ0 = 1550 nm achieve a 3-dB bandwidth of 210 GHz, an insertion loss of 3 dB, and an extinction ratio of 5 dB for an overall length of < 4 μm as predicted by the SPC model. Our results illustrate trade-offs between high-speed modulator operation and low insertion loss, vs. extinction ratio, and the need for precise modelling of carrier distributions in ENZ materials.

J. Tippinit, M. Kuittinen, M. Roussey

We present the design and simulations of a novel integrated device concept enabling a frequency conversion of a broad signal. The solution is based on a hybrid silicon–graphene photonic chip, which could be used for controlled spectrometry in low-cost devices. The device is based on a silicon-on-insulator (SOI) platform on which an arrayed waveguide grating (AWG) is designed for operation at the center wavelength of λ = 1800 nm. The AWG is spectrally separating one broad input signal to thirty-two-output channels with a channel spacing of 2.72 nm. The output signals are well separated and uniform with the extinction ratio and the standard deviation of 10.00 dB and 0.04, respectively. The 3 dB channel width is 1.34 nm, which is suitable for sensing applications with significant accuracy. After spacial and spectral separation, each output signal is then converted to one signal at 1480 nm wavelength through a graphene-based saturable absorber scheme. Therefore, the device allows the detection of each separated signal with a simple near-infrared camera on which the outputs are imaged using conventional optics, leading to a classical pixel/wavelength correspondence. Crossed-waveguide couplers are designed to combine the controlling signal at 1480 nm to each channel waveguide of the AWG. The combination of the signals saturates the graphene layer at the output waveguides, allowing the pass of the controlling wavelength. This device can be applied as a spectrometer in environmental sensing and monitoring with high efficiency and low cost.

Zhu Ming-Jie, Zhao Wei, Wang Zhi-hai

In the traditional quantum optics and waveguide QED, the atom is usually considered as a point like dipole. However, the successful coupling between a superconducting transmon and surface acoustic wave give the birth to the giant atom, which interacts with the waveguide via more than two points. In the giant atom setup, the dipole approximation breaks down the nonlocal light-matter interaction has brought lots of unconventional quantum effects, which is presented by the phase interference. As a simplification, the giant resonator, which supports equal energy interval, can be regarded as a linear version of the giant atom. Similar to the giant atom system, the giant resonator also couples to the resonator array waveguide via two sites. Based on the quantum interference effect, we study the phase control in giant resonator and the cavities in the waveguide. For the three coupled resonator system, we reveal the character of the steady state when the driving and dissipation are both present via the Heisenberg-Langevin equations. In such a system, the steady state can be coherently control by adjusting the phase difference $\phi$ between the two classical driving fields. We analytically give the condition for the existence of dark cavity. The results show that only when the middle cavity and the giant resonator are both ideal, one can realize the flash and shielding. Furthermore, we generalize the above study in three resonator system to the multiple cavity system to investigate the photonic flash and shielding. We find that when the number of the middle resonators is $4n+1\, n\in Z$, the bidirectional photonic shielding occurs, that is the giant resonator can shield the middle resonators in the waveguide and vice versa. On the contrary, when there are $4n+3$ middle resonators in the giant resonator regime, only the directional photonic shielding happens, that is, the giant resonator can shield the waveguide, but the waveguide can not shield the giant resonator. The above interesting photonic flash and shielding comes from the quantum interference effect. That is, the driving field inject the photon to the waveguide, and the photon propagates in different directions. In the overlapped regime, the photon carrying different phase undergoes destructive interference and plays as a dark resonator. We hope the interference based photonic control scheme can be applied in the field of quantum device designing.

Muhammad Saadi, Sushank Chaudhary, Santosh Kumar

This Research Topic on “Applications of Photonic Sensors in Smart Cities” belongs to the journals, Frontiers in Communications and Networks and Frontiers in Physics. For this Research Topic serves as lead guest editor and other guest editors include Saadi et al. Demostenes Z. Rodriguez, Lunchakorn Wuttisittikulkij, and Tien Khee Ng. The aim of this Research Topic is to highlight recent advancements in the field of Quantum Optics and Information, Photonic sensors, and optical wireless communication and how they can contribute tomaking smart cities.We received an overwhelming response to our call for papers and, after a rigorous peer review process, eight papers were selected for this Research Topic. The managing editor, Saadi et al. and the guest editors would like to thank all authors who submitted their papers to this Research Topic. Thanks are also due to all anonymous reviewers, whose timely feedback ensured the high quality of the journal, and the Frontiers publication team for helping this issue to be a success. All the Guest Editors hope that this Research Topic can provide an in-depth insight into the field of optical wireless communication, photonic sensors, and optoelectronics that help realize the vision of smart cities. The first paper title is “Calculation of the Coupling Coefficient in Step-Index Multimode Polymer Optical Fibers Based on the Far-Field Measurements”, in which the authors use the power flow equation (PFE) to investigate mode coupling in step-index multimode polymer optical fiber. The second accepted paper title is “Porous Silicon–Based Microring Resonator for Temperature and Cancer Cell Detection”, in which a microring resonator sensor based on porous silicon is proposed for temperature and cancer cell detection, simultaneously. The results presented in this paper are promising, suggesting that the microring resonator sensor can be used in the fields of environment sensing, temperature sensing, chemical sensing, and biosensing. The third accepted paper title is “Broadband Coherent Mid-Infrared Supercontinuum Generation in All-Chalcogenide Microstructured Fiber with All-Normal Dispersion”, in which a numerical demonstration of the generation of broadband coherent supercontinuum (SC) spectra in the mid-infrared region using dispersion-engineered all-chalcogenide microstructured fibers (MOFs) is presented. Such sources can be applied in frequency metrology, optical coherence tomography, biomedical imaging, and few-cycle pulse compression. OPEN ACCESS

Gerard R. Lemaitre, Pascal Vola, Patrick Lanzoni

We present new results obtained from the modeling of a <i>tulip-like</i> variable curvature mirror (VCM) in the case of a central force that reacts to its contour. From Nastran finite element analysis, we shows that 3-D optimizations, using <i>non-linear static flexural option</i>, with an appropriate solution sequence, provide an accurate <i>tulip-like</i> VCM thickness distribution. This allows us to take into account boundary conditions, including the thin outer collarette and its link to a rigid ring. Modeling with a quenched stainless steel chromium substrate provides diffraction-limited optical surfaces. Rayleigh’s quarter-wave criterion is performed over a <i>zoom range</i> from flat up to <i>f</i>/3.5 convexity over a 13 mm clear aperture and 10 daN central force. The optical testing results of a prototype <i>tulip-like</i> VCM elaborated from the previous analytic theory, show quasi-diffraction-limited figures for a zoom range up to <i>f</i>/5. The present modeling results should significantly help in the future construction of such VCMs with a zoom range extended up to <i>f</i>/3.5.

Lei-Ming Zhou, Yaqiang Qin, Yuanjie Yang et al.

Particles trapped by optical tweezers, behaving as mechanical oscillators in an optomechanical system, have found tremendous applications in various disciplines and are still arousing research interest in frontier and fundamental physics. These optically trapped oscillators provide compact particle confinement and strong oscillator stiffness. But these features are limited by the size of the focused light spot of a laser beam, which is typically restricted by the optical diffraction limit. Here, we propose to build an optical potential well with fine features assisted by the nonlinearity of the particle material, which is independent of the optical diffraction limit. We show that the potential well shape can have super-oscillation-like features and a Fano-resonance-like phenomenon, and the width of the optical trap is far below the diffraction limit. A particle with nonlinearity trapped by an ordinary optical beam provides a new platform with a sub-diffraction potential well and can have applications in high-accuracy optical manipulation and high-precision metrology.

Wen Qi Zhang, Zane Peterkovic, Stephen C. Warren-Smith et al.

We propose a new concept to generate efficient one-third harmonic light from an unseeded third harmonic process in optical fibers. Our concept is based on the dynamic constant (Hamiltonian) of the nonlinear third harmonic generation in optical fibers and includes a periodic array of nonlinear fibers and phase compensation elements. We test our concept with a simulation of the nonlinear interaction between the fundamental and third harmonic modes of a realistic optical fiber, demonstrating high-efficiency one-third harmonic generation. Our work opens a new approach to achieving the so far elusive one-third harmonic generation in optical fibers.

T. Murai, Y. Shoji, T. Mizumoto

Thermomagnetic recording is a technique used as a writing process for magneto-optical (MO) drives. Despite their significant advantages, such as rewritability, nonvolatility, reliability, and large cycling endurance, MO drives are rarely used today because of the complex drive systems that must deal with magnetic field and lightwave simultaneously. This study reports on the light-induced thermomagnetic recording of a ferromagnetic thin-film CoFeB on a Si photonic platform. Lightwave guided in the Si waveguide evanescently coupled to the thin-film magnet and underwent optical absorption, resulting in heating and a decrease in coercive force. Therefore, we observed magnetization reversal with an applied magnetic field for both continuous and modulated light pulses using a magneto-optical Kerr effect microscope, and the light-induced thermomagnetic recording was experimentally demonstrated on a Si photonic platform. The proposed scheme enables the realization of on-chip MO memories on the Si photonic platform in which neither bulky free-space optics nor mechanical rotation systems are required.

Anup M. Upadhyaya, M. Hasan, S. Abdel-Khalek et al.

This study presented an overview of current developments in optical micro-electromechanical systems in biomedical applications. Optical micro-electromechanical system (MEMS) is a particular class of MEMS technology. It combines micro-optics, mechanical elements, and electronics, called the micro-opto electromechanical system (MOEMS). Optical MEMS comprises sensing and influencing optical signals on micron-level by incorporating mechanical, electrical, and optical systems. Optical MEMS devices are widely used in inertial navigation, accelerometers, gyroscope application, and many industrial and biomedical applications. Due to its miniaturised size, insensitivity to electromagnetic interference, affordability, and lightweight characteristic, it can be easily integrated into the human body with a suitable design. This study presented a comprehensive review of 140 research articles published on photonic MEMS in biomedical applications that used the qualitative method to find the recent advancement, challenges, and issues. The paper also identified the critical success factors applied to design the optimum photonic MEMS devices in biomedical applications. With the systematic literature review approach, the results showed that the key design factors could significantly impact design, application, and future scope of work. The literature of this paper suggested that due to the flexibility, accuracy, design factors efficiency of the Fibre Bragg Grating (FBG) sensors, the demand has been increasing for various photonic devices. Except for FBG sensing devices, other sensing systems such as optical ring resonator, Mach-Zehnder interferometer (MZI), and photonic crystals are used, which still show experimental stages in the application of biosensing. Due to the requirement of sophisticated fabrication facilities and integrated systems, it is a tough choice to consider the other photonic system. Miniaturisation of complete FBG device for biomedical applications is the future scope of work. Even though there is a lot of experimental work considered with an FBG sensing system, commercialisation of the final FBG device for a specific application has not been seen noticeable progress in the past.

Satish Addanki, I. Amiri, P. Yupapin

Abstract The optical fibers which are considered as waveguides can be applied to light transmission applications. The core part of the optical fiber is surrounded by a glass or plastic layer called cladding which is characterized by the refractive index that is lower compared to the core refractive index. The total internal reflection phenomena are necessary for the fine confinements of the light within the waveguide. Basically, optical fibers can be categorized based on the structure, modes number, refractive index profile, dispersion, signal processing ability, and polarization. In this report, we focus on the first three common types of optical fibers. As a common application of the fibers, these can be used in fiber lasers to create and amplify a narrow intense beam of coherent and monochromatic light. Fabrication of optical fiber involves three stages such as the preform formation. Modified chemical vapor deposition (MCVD) method is a known technique, which can be used to fabricate the optical fibers. Optical fiber sensors are well known for wide range applications in optics and photonics. As a sensing application, optical biosensors can be made based on the refractive index changes that used widely for detection of biomolecules in their natural forms.

Yifan Wang, Shi-ze Yang, P. Crozier

Nanoscale optics can be applied to various fields, e

Hao Chen, Ziming Zhang, Guoqing Wang et al.

Gradient-based optimization combined with the adjoint method has been demonstrated to be an efficient way to design a nano-structure with a vast number of degrees of freedom. However, most inverse-designed photonic devices are applied as linear photonic devices. Here, we demonstrate the nonlinear optical response in inverse-designed integrated splitters fabricated on a SiN platform. The splitting ratio is tunable under different incident powers. The thermo-optical effect can be used as an effective approach for adjusting the nonlinear optical response threshold and modulation depth of the device. These promising results indicate the great potential of inverse-designed photonic devices in nonlinear optics and optical communications.