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![Figure 1. The past and predicted growth of the total Internet traffic [1].](publication/301895458/figure/fig12/AS:358753745555459@1462544966536/The-past-and-predicted-growth-of-the-total-Internet-traffic-1_Q320.jpg)
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Lightwave communications is a necessity for the information age. Optical links provide enormous bandwidth, and the optical fiber is the only medium that can meet the modern society's needs for transporting massive amounts of data over long distances. Applications range from global high-capacity networks, which constitute the backbone of the in...
Citations
... Light-control technologies have been used in a wide variety of applications. These include machine vision [1,2], optical computing [3,4], telecommunications [5,6], holographic data storage [7,8], sensing [9,10] and monitoring process analysis [11,12]. The light phase control method uses passive devices, such as diffraction elements [13,14] and active electro-optical devices [15,16]. ...
Liquid crystal waveguide film that we can control through wide visible wavelength has been proposed. Recently, small optical system is needed for various industrial application. Among the application, liquid crystal is the material for controlling optical ray. The application includes optical switch and display by controlling birefringence. These applications include AR/VR display, for manufacturing, inspection, and so on. In this study, we have investigated liquid crystal (LC) waveguide film that light is emitted from the waveguide film on glasses toward the eye when the power is turned on. The cut-off of waveguide film is based on liquid crystal switch using refractive index anisotropy. We select smart glasses as one of the applications for AR/VR display. The potential of LC waveguide films is demonstrated by simulating the propagation characteristics of waveguides film, LC reorientations, and diffraction gratings in the field of RGB wavelength range. By using the waveguide structure, the film thickness can be configured to be less than 1 mm. We can expect the liquid crystal waveguide has much application to optical integrated circuit as other application except for smart glasses.
... Coherent optical orthogonal frequency division multiplexing (CO-OFDM) systems are widely used in high-speed and long-distance transmission [1][2][3][4][5], and the importance of solving security problems in the transmission process has emerged. The physical layer is at the bottom of the open system interconnect (OSI) model, and to completely secure the transmitted data, the advantages of research methods for encryption of the physical layer are highlighted [6]. ...
In this paper, we propose a camera projection approach to enhance the physical layer security of coherent optical orthogonal frequency division multiplexing (CO-OFDM) systems. The data are converted to the new location by the camera projection module in the encryption system, where the 5D hyperchaotic system provides the keys for the camera projection module. The simulated 16QAM CO-OFDM security system over 80 km SSMF is shown to provide a key space of about 9 × 10^90 through the five-dimensional (5D) hyperchaotic system, making it impossible for eavesdroppers to obtain valid information, and the peak-to-average power ratio (PAPR) is reduced by about 0.8 dB.
... Starting with the visionary paper of Charles Kao in 1966 [1,2], the development of singlemode optical fibers has truly revolutionized optics, enabling optical telecommunication over transcontinental distances [3], fiber-based optical combs [4] for precision metrology as well as ultrafast fiber lasers [5]. Giving rise to the formation of optical solitons [6], the all-optical Kerr nonlinearity plays a pivotal role in the latter two applications of fibers. ...
Recent years have seen a resurgence of interest in multimode fibers due to their intriguing physics and applications, with spatial beam self-cleaning (BSC) having received special attention. In BSC light condenses into the fundamental fiber mode at elevated intensities. Despite extensive efforts utilizing optical thermodynamics to explain such counterintuitive beam reshaping process, several challenges still remain in fully understanding underlying physics. Here we provide compelling experimental evidence that BSC in a dissipative dual-core fiber can be understood in full analogy to Bose-Einstein condensation (BEC) in dilute gases. Being ruled by the identical Gross-Pitaevskii Equation, both systems feature a Townes soliton solution, for which we find further evidence by modal decomposition of our experimental data. Specifically, we observe that efficient BSC only sets in after an initial thermalization phase, causing converge towards a Townes beam profile once a threshold intensity has been surpassed. This process is akin to a transition from classical to quantum-mechanical thermodynamics in BEC. Furthermore, our analysis also identifies dissipative processes as a crucial, yet previously unidentified component for efficient BSC in multimode fiber. This discovery paves the way for unprecedented applications of multimode-fiber based systems in ultrafast lasers, communications, and fiber-based delivery of high-power laser beams.
... As the system capacity and complexity continue to increase in the ever-evolving landscape of optical communications, both academic and industrial requirements for understanding, configuring, evaluating, and optimizing the optical fiber communication systems have become increasingly significant [1], involving multiple intricate tasks, such as the optical transmission systems simulation, digital signal processing (DSP) algorithms verification, system performance evaluation, and quality of transmission (QoT) optimization. In the academic community, accurate, fast and convenient system simulation and evaluation have significant reference value for researchers to investigate the uncertain transmission systems, theoretically validate new algorithms, and predict experimental results. ...
With the increasing capacity and complexity of optical fiber communication systems, both academic and industrial requirements for the essential tasks of transmission systems simulation, digital signal processing (DSP) algorithms verification, system performance evaluation, and quality of transmission (QoT) optimization are becoming significantly important. However, due to the intricate and nonlinear nature of optical fiber communication systems, these tasks are generally implemented in a divide-and-conquer manner, which necessitates a profound level of expertise and proficiency in software programming from researchers or engineers. To lower this threshold and facilitate professional research easy-to-start, a GPT-based versatile research assistant named OptiComm-GPT is proposed for optical fiber communication systems, which flexibly and automatically performs system simulation, DSP algorithms verification, performance evaluation, and QoT optimization with only natural language. To enhance OptiComm-GPT’s abilities for complex tasks in optical fiber communications and improve the accuracy of generated results, a domain information base containing rich domain knowledge, tools, and data as well as the comprehensive prompt engineering with well-crafted prompt elements, techniques, and examples is established and performs under a LangChain-based framework. The performance of OptiComm-GPT is evaluated in multiple simulation, verification, evaluation, and optimization tasks, and the generated results show that OptiComm-GPT can effectively comprehend the user’s intent, accurately extract system parameters from the user’s request, and intelligently invoke domain resources to solve these complex tasks simultaneously. Moreover, the statistical results, typical errors, and running time of OptiComm-GPT are also investigated to illustrate its practical reliability, potential limitations, and further improvements.
... Thus, this is called the parallel resonant frequency . The piezoelectric coupling efficiency is conventionally characterized by the figure of merit called 2 ,eff , which is related with the difference between and as: ...
... This is due to the HBAR resonances from the Si substrate since part of the contact pads and traces are not released. The electromechanical coupling efficiency 2 ,eff is calculated based on the Mason model [217] for released and unreleased structures, as shown in Fig. 38(f). The efficiency is maximized around the AlN resonance at 4 GHz and improved by more than one order of magnitude upon releasing. ...
Recent decades have seen significant advancements in integrated photonics, driven by improvements in nanofabrication technology. This field has developed from integrated semiconductor lasers and low-loss waveguides to optical modulators, enabling the creation of sophisticated optical systems on a chip scale capable of performing complex functions like optical sensing, signal processing, and metrology. The tight confinement of optical modes in photonic waveguides further enhances the optical nonlinearity, leading to a variety of nonlinear optical phenomena such as optical frequency combs, second-harmonic generation, and supercontinuum generation. Active tuning of photonic circuits is crucial not only for offsetting variations caused by fabrication in large-scale integration, but also serves as a fundamental component in programmable photonic circuits. Piezoelectric actuation in photonic devices offers a low-power, high-speed solution and is essential in the design of future photonic circuits due to its compatibility with materials like Si and Si3N4, which do not exhibit electro-optic effects. Here, we provide a detailed review of the latest developments in piezoelectric tuning and modulation, by examining various piezoelectric materials, actuator designs tailored to specific applications, and the capabilities and limitations of current technologies. Additionally, we explore the extensive applications enabled by piezoelectric actuators, including tunable lasers, frequency combs, quantum transducers, and optical isolators. These innovative ways of managing photon propagation and frequency on-chip are expected to be highly sought after in the future advancements of advanced photonic chips for both classical and quantum optical information processing and computing.
... Owing to the consistent and rapid growth of network traffic, the transmission capacity of the wavelength-division multiplexing (WDM) optical transmission system based on single-mode fiber has been rapidly approaching its theoretical limits [1]. To address this issue, mode-division multiplexing (MDM) technology has been proposed and gained widespread attention recently [2,3]. ...
In this paper, we propose a thermo-optic reconfigurable three-mode (de)multiplexer based on an asymmetrical horizontal three-waveguide directional coupler that includes two identical single-mode waveguides and a three-mode waveguide. Over the whole wavelength range of 1540–1560 nm, and for the TE (TM) polarization, our typical fabricated device with polymer material shows coupling efficiencies as high as 94% (93%) and 93% (92%) for the mode conversions of ${{\rm LP}_{01}} {-} {{\rm LP}_{11{\rm a}}}$ L P 01 − L P 11 a and ${{\rm LP}_{01}} {-} {{\rm LP}_{11{\rm b}}}$ L P 01 − L P 11 b , with the heating powers of 53.57 mW and 71.19 mW, respectively. Our proposed device can be employed in the fields of reconfigurable mode-division multiplexing systems.
... Fiber optics has been one of the most promising and rapidly developing high-tech industries for the last couple of decades [1][2][3]. This is due to the ever-increasing application of fiber optic technologies in various sectors of the economy: communications [4,5], navigation [6], medicine [7], new materials [8,9], fiber sensorics [10][11][12][13], etc. [14,15]. ...
The effective control of any technological process is essential in ensuring high-quality finished products. This is particularly true in manufacturing knowledge-intensive and high-tech products, including microstructured photonic crystal fibers (PCF). This paper addresses the issues of stabilizing the optimal control of the silica capillary drawing process. The silica capillaries are the main components of PCF. A modified mathematical model proposed by the authors is used as the basic model of capillary drawing. The uniqueness of this model is that it takes into account the main forces acting during drawing (gravity, inertia, viscosity, surface tension, pressure inside the drawn capillary), as well as all types of heat transfer (heat conduction, convection, radiation). In the first stage, the system of partial differential equations describing heat and mass transfer was linearized. Then, the problem of the optimal control of the drawing process was formulated, and optimization systems for the isothermal and non-isothermal cases were obtained. In the isothermal case, optimal adjustments of the drawing speed were obtained for different objective functionals. Thus, the proposed approach allows for the constant monitoring and adjustment of the observed state parameters (for example, the outer radius of the capillary). This is possible due to the optimal control of the drawing speed to obtain high-quality preforms. The ability to control and promptly eliminate geometric defects in the capillary was confirmed by the analysis of the numerical calculations, according to which even 15% deviations in the outer radius of the capillary during the drawing process can be reduced to 4–5% by controlling only the capillary drawing speed.
... One of the key applications for vortex laser beams in the near-infrared (1.5-2 µm) wavelength range is optical communications [30,31]. This is due to commercial quartz optical fibers having low loss in this wavelength band, and the OAM characteristics of these beams can be used as an additional degree of freedom for carrying information [32,33]. Vortex beams operating in the mid-infrared region have potential use in applications including quantum optics, materials processing, novel medical diagnosis and treatment, and infrared optoelectronic countermeasures. ...
In this paper, we present a picosecond pulsed, synchronously pumped optical parametric oscillator producing vortex beam output with tunable wavelengths in the near- to mid-infrared range. The system utilizes a Nd:YVO4 picosecond pulsed solid-state laser emitting at a wavelength of 1.064 µm to pump a Z-shaped, singly resonant OPO which contains a MgO:PPLN crystal with a fan-shaped grating. The wavelength tuning characteristics of the OPO output are examined both as a function of the MgO:PPLN grating period and crystal temperature. The orbital angular momentum of the pump field can be selectively transferred to either the signal or idler fields by appropriately adjusting the location of the MgO:PPLN crystal within the OPO cavity. The maximum output power of the signal and idler vortex fields are 5.12 W and 3.46 W, respectively, for an incident pump power of 19 W.
... An unique characteristics of PCF are huge light-interaction areas, unending single mode, adjustable dispersion, large birefringence, great discontinuity, and enormous optimal mode regions, and low losses [3,4]. These characteristics address the traditional limitations like scattering along with absorption in a communications system [5,6]. Besides telecommunication applications, PCF is used as use very sensitive, small-sized sensor devices in a variety of uses [7]. ...
air holes of hybrid hexagonal cladding is used in the design of the sensor. The suggested sensor, operating at the optimal frequency of 3.4 THz, demonstrated a maximum sensitivity of 99.58% and extremely poor TL of 2.326 × 10-3 cm −1. As a result of the circular shapes for cladding as well as core air holes, the sensor minimizes fabrication complexity and loss while maintaining maximum sensitivity. Because it is simple to manufacture and can be utilized for testing at petrol pumps for Measures of admixture, this proposed PCF design will be extremely useful in the future and assist to please customers. Abstract This study has clarified the design of a new hybrid hexagonal PCF sensor with circular hollow core. Hollow-core photonic crystal fiber (HC-PCFs) offer compact designs with reduced nonlinearities and tailored dispersion , enabling high-power lasers and dispersion management. This detector is use to detect fuel adulteration in THz region. Due to its large circular core, it gives notable performance. PCF sensor provides maximum relative sensitivity about 99.58% with very low confinement loss of 7.3536 × 10-12 cm −1 and total loss of 2.326 × 10-3 cm −1 at optimum frequency 3.4 THz. The air filling fraction for the propose sensor is 0.96 with spot size of 1.5494 × 10-4 μm. Our proposed detector has ultra sensing ability to detect kerosene adulteration. A huge circle air hole and circular core
... Photonics is a well-established field, transversing various science and technology domains, such as optical communications [1,2]. Since 2020, internet traffic has rocketed, mainly due to the increase in many digital activities because of the lockdowns and restrictions provoked by the coronavirus pandemic [3]. ...
This study investigates the potential of a set of pseudo-stilbene and azobenzene molecular structures to become optical frequency converters for optical communications based on a detailed exploration of the first-order molecular hyperpolarizability (β_HRS), which is the microscopic counterpart of second harmonic generation (SHG). β_HRS values were obtained by employing quantum chemical calculations using the Gaussian 16 software package in solvent and gas-phase medium at different wavelengths, such as 1064 nm, 1310 nm, and 1510 nm. The latter two wavelengths are of particular interest to optical communications.
