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- 摘要
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- 实验方案
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[IEEE 2018 Asia Communications and Photonics Conference (ACP) - Hangzhou, China (2018.10.26-2018.10.29)] 2018 Asia Communications and Photonics Conference (ACP) - Supercontinuum generation triggered by a weak 100-kHz linewidth continuous-wave
摘要： We experimentally and numerically demonstrate efficient supercontinuum generation in highly nonlinear dispersion-shifted fiber triggered by a weak 100-kHz linewidth continuous-wave at the 10-7 level relative to the pump, which is the lowest power reported.
关键词： Four-wave mixing,Nonlinear optics,Supercontinuum generation
更新于2025-11-28 14:23:57
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Long tapered fiber with array of FBG
摘要： A tapered optical fiber with an adiabatic transition from single-mode to a few-mode part has been fabricated with an array of fiber Bragg gratings being inscribed during the drawing process. We demonstrate that the propagating optical signal remains single-mode along the tapered fiber FBG array even in a multimode part of it. The spectral width of the reflected signal from the tapered optical fiber is 4 nm. The level of the reflected signal is up to 5% at some wavelengths.
关键词： Tapered optical fibers,Fiber optics sensors,Fiber Bragg gratings
更新于2025-11-28 14:23:57
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Arc-Induced Long Period Gratings in Erbium-Doped Fiber
摘要： In this paper, we report about the fabrication of long period gratings (LPGs) directly into an Erbium-doped fiber, by using the electric arc discharge technique. The attention is focused on the writing process and the resulting properties, by considering gratings with different periods and measuring their spectra over a wide wavelength range. The LPGs show high order attenuation bands with tunable resonance wavelengths and depths up to 30 dB, while the lengths of the final devices are in range 20–45 mm. The polarization-dependent loss of these LPGs is also measured, for the first time in this kind of fiber. As further novelty, the influence of surrounding refractive index, applied strain, and temperature is investigated and discussed in comparative manner. Based on the achieved results, this fabrication procedure can be adapted to a specific application, for example in optical communications, signal processing, and sensing fields.
关键词： waveguide devices,Fiber gratings,fiber optics systems,sensors
更新于2025-11-28 14:23:57
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In-fiber Mach-Zehnder Interferometer Exploiting a Micro-cavity For Strain and Temperature Simultaneous Measurement
摘要： An in-fiber Mach-Zehnder interferometer (MZI) with a micro-cavity (MC) exploited for strain and temperature simultaneous measurement. The research is carried out experimentally and simulatively. The MC fabricated by splicing a hollow quartz tube between two single mode fibers serves as a light splitter for the two arms of MZI beams and a Fabry–Pérot interferometer (FPI) component at the same time. Thus both functions of a Mach-Zehnder interferometer and a Fabry–Pérot interferometer were implemented in a single sensor. With aid of the different response of the MZI and FPI to the strain and temperature, this device can achieve a simultaneous measurement and the strain/temperature cross-sensitivity issue has been alleviated. Such a composite interference structure, possess with the characteristics of easy making, high performance-price ratio provides a promising approach to implement strain and high-temperature simultaneous measurement.
关键词： Fabry–Pérot interferometer,Fiber Optics Sensors,Mach-Zehnder interferometer
更新于2025-11-28 14:23:57
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Scaling effects on the optical properties of patterned nano-layered shape memory films
摘要： Nano-layered films of PVAc/PU systems were fabricated by forced assembly coextrusion method. The bulk shape memory properties of PVAc/PU systems were utilized to program nanoscale patterns such as diffraction grating which exhibit iridescence after patterning. A hot embossing process has been utilized to imprint diffraction grating patterns as nano-scale information onto the surface of the thin multilayer films. Three levels of hierarchy i.e. layer thickness, spacing and heights of patterns, governs the functionality of the patterned multilayer film. The time and temperature dependent viscoelastic shape memory behavior determines the opto-mechanical tunability of the film. Mechanical switching of the patterns also leads to optical switching of the films which corresponds to their efficiency of information retrieval. The recovery of patterns as well as the diffractive property depends on the layer thickness (l) of films and heights of patterns (h0). The results illustrate that the higher ratio of h0/l better is the recovery of the grating patterns and the corresponding diffractive properties. This scaling effect enables versatile applications in information security by tuning the layer structure of the multilayer shape memory films.
关键词： scaling effect,shape memory film,pattern programming,hot embossing,multilayer film,information security,diffractive optical element,thermal responsive optics
更新于2025-10-22 19:40:53
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Synthesis and characterization of Er3+/Cu+-codoped fluorophosphate glasses
摘要： NaPO3-ZnF2 binary fluorophosphate glasses doped with trivalent erbium and monovalent copper were synthesized by the conventional melting and casting method using ErF3 and CuCl as starting materials. The samples were systematically investigated using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. X-ray powder diffraction patterns confirmed that the as-prepared compounds were all amorphous. The glass transition temperature (Tg) was observed around 230°C by DSC analysis, while the thermal stability range (?T) was estimated to be between 90 and 140 °C. The measured value of the refractive index (n) was measured as 1.502 at a wavelength of 632.8 nm. Thermal annealing of the samples was performed at different temperatures above Tg for various heat-treatment times. During these steps, monovalent copper and sodium ions were expected to be reduced, forming metallic nanoparticles. This transformation lead to coloration changes, depending on the annealing time and temperature, with respect to the transparency of the glasses. These spectroscopic changes are related to the plasmonic effects induced by the presence of both Cu and Na metallic nanoparticles, which promote red shift due to absorption. The VIS-NIR absorption spectra of the prepared glasses were investigated in the frame work of standard Judd-Ofelt (J-O) theory, which was used to determine the J-O intensity parameters, radiative transition probabilities and branching ratios for Er3+ ions embedded in the glasses. The calculated intensity parameters (Ω2,4,6) were compared to those obtained for Er3+ in several other glasses.
关键词： Nanoparticles,Fluorophosphate glasses,Absorption,Judd-Ofelt theory,Optics
更新于2025-10-22 19:40:53
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One-dimensional integrals to calculate the two-dimensional Rayleigh–Sommerfeld diffraction integrals for non-rotationally symmetric functions and general polarizing illuminating fields
摘要： The recently reported (Alcalá Ochoa, 2018) approximation to the Rayleigh–Sommerfeld diffraction integrals (RSDI) is used to obtain a set of expressions to calculate the diffraction properties of non-rotationally symmetric optical systems illuminated with polarization fields. It is proved that the three two-dimensional integrals of RSDI can be expressed accurately from two to eight one-dimensional integrals depending of the type of polarization studied. It is proved also that previous developments based on Taylor’s approximations to the RSDI can be described by these new expressions.
关键词： Imaging optics,Diffraction,Fourier optics,Physical optics,Microscopy
更新于2025-09-23 15:23:52
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Performance of Bandwidth Extension Techniques for High-Speed Short-Range IM/DD Links
摘要： In recent years, advanced modulation formats for short-range high-speed communications have been increasingly discussed to achieve the transmission rates needed to satisfy the future demand of broadband services. A key parameter in such applications is the use of low-cost optical components, which mainly means the use of intensity modulation (IM) and direct detection (DD) schemes. In order to exploit the available bandwidth offered by the latest optical components, high-speed data converters (DAC and ADC) are required. However, the available bandwidth of DACs and ADCs is generally smaller, than that of their optical counterparts, resulting in a capacity bottleneck. This issue can be addressed by bandwidth extension techniques, which enable the full use of the optical components. In this paper, two high-speed systems are presented and experimentally analyzed for an optical link based on IM/DD, utilizing a bandwidth extension technique based on electrical up/down-conversion and passive signal combining. The experiment for the first system uses two independent sub-signals, with a total bandwidth beyond 40 GHz and enables transmission rates up to 180 Gb/s. Different aspects of the system are highlighted including general performance, transmission distance, use of different modulation formats and the influence of important components. For the second system, the experiment consists of the generation of a spectrally continuous pulse amplitude modulation (PAM) signal with the help of two sub-signals and its transmission over an optical IM/DD link. The challenges and requirements for hardware and software are discussed and the impact of power and phase mismatches between both sub-signals are investigated as well.
关键词： Fiber optics and optical communications,Fiber optics links and subsystems
更新于2025-09-23 15:23:52
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Control of the creation of bottle-hollow beam by polarization shaping
摘要： We propose a method for generating bottle-hollow (BH) beams by tailoring the polarization state of the incident field in a tightly focused system. An optical BH field can be generated in the vicinity of the focus by tailoring azimuthal and radial polarization indices of the incident field. Calculations show that the length and diameter are mainly affected by the radial polarization index. While for the azimuthal index, it affects the width of the hollow greatly. As a result, an all-optical controlled tunable BH beam is achieved. The generated BH beam may find application in optical tweezers.
关键词： Diffractive optics,Singular optics.,Polarization,Propagation
更新于2025-09-23 15:23:52
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Complex Inverse Design of Meta-optics by Segmented Hierarchical Evolutionary Algorithm
摘要： With the recent burgeoning advances in nano-optics, ultracompact, miniaturized photonic devices with high-quality and spectacular functionalities are highly desired. Such devices’ design paradigms often call for the solution of a complex inverse nonanalytical/semianalytical problem. However, currently reported strategies dealing with amplitude-controlled meta-optics devices achieved limited functionalities mainly due to restricted search space and demanding computational schemes. Here, we established a segmented hierarchical evolutionary algorithm, aiming to solve large-pixelated, complex inverse meta-optics design and fully demonstrate the targeted performance. This paradigm allows significantly extended search space at a rapid converging speed. As typical complex proof-of-concept examples, large-pixelated meta-holograms are chosen to demonstrate the validity of our design paradigm. An improved fitness function is proposed to reinforce the performance balance among image pixels, so that the image quality is improved and computing speed is further accelerated. Broadband and full-color meta-holograms with high image fidelities using binary amplitude control are demonstrated experimentally. Our work may find important applications in the advanced design of future nanoscale high-quality optical devices.
关键词： full-color meta-holograms,fast-converging algorithm,meta-optics,segmented hierarchical evolutionary algorithm,complex large-pixelated inverse design
更新于2025-09-23 15:23:52