- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2018 Asia Communications and Photonics Conference (ACP) - Hangzhou, China (2018.10.26-2018.10.29)] 2018 Asia Communications and Photonics Conference (ACP) - Wide-Spectrum Pulsed Fiber Laser based on Picosecond Pulse Generation Supercontinuum
摘要： We demonstrated a wide-spectrum pulsed fiber laser by using supercontinuum (SC) generate from a narrow pulse width fiber laser pump into high nonlinear fiber (HNLF). The pulse width of wide-spectrum pulsed fiber laser is 7.95ps and the repetition frequency is 4GHz with a 20nm bandwidth. It is found that the anomalous dispersion region near the zero dispersion wavelength has a better stability by observing the wide spectrum pulses in different bands.
关键词： different dispersion region,super-continuum,wide-spectrum pulsed fiber laser,narrow pulse width
更新于2025-11-28 14:24:03
-
Physical origin of higher-order soliton fission in nanophotonic semiconductor waveguides
摘要： Supercontinuum generation in Kerr media has become a staple of nonlinear optics. It has been celebrated for advancing the understanding of soliton propagation as well as its many applications in a broad range of fields. Coherent spectral broadening of laser light is now commonly performed in laboratories and used in commercial “white light” sources. The prospect of miniaturizing the technology is currently driving experiments in different integrated platforms such as semiconductor on insulator waveguides. Central to the spectral broadening is the concept of higher-order soliton fission. While widely accepted in silica fibers, the dynamics of soliton decay in semiconductor waveguides is yet poorly understood. In particular, the role of nonlinear loss and free carriers, absent in silica, remains an open question. Here, through experiments and simulations, we show that nonlinear loss is the dominant perturbation in wire waveguides, while free-carrier dispersion is dominant in photonic crystal waveguides.
关键词： nonlinear optics,Supercontinuum generation,free-carrier dispersion,soliton fission,semiconductor waveguides
更新于2025-11-28 14:24:03
-
An optical angle sensor based on chromatic dispersion with a mode-locked laser source
摘要： This paper proposes a new optical angle sensor, in which a mode-locked laser is employed as the light source, and chromatic dispersion of a collimator objective is utilized to detect the angular displacement of a target of interest. In the proposed method, each of the optical modes in the femtosecond laser beam reflected from the reflector mounted on a target of interest is separated from the others by chromatic dispersion of a collimator objective to generate a group of focused laser beams that can be utilized as the scale for measurement of an angular displacement of the target. By detecting the change in peak frequency in optical spectra obtained by the photodetector, a small angular displacement can be measured. In this paper, as the first step of research, a prototype optical setup is developed, and some basic experiments are carried out to demonstrate the feasibility of the proposed method for measurement of angular displacement.
关键词： Chromatic dispersion,Angular displacement,Angle measurement,Optical frequency comb,Laser autocollimation
更新于2025-11-28 14:24:03
-
Effects of annealing conditions on the oxygen evolution activity of a BaTaO2N photocatalyst loaded with cobalt species
摘要： Precise engineering of the cocatalyst-photocatalyst interface and optimization of the cocatalyst dispersion are essential for improving the activity of particulate semiconductor photocatalysts. Herein, we report the effects of varying the conditions used to load cobalt oxide (CoOx) as a cocatalyst on the O2 evolution activity of a particulate BaTaO2N photocatalyst, based on trials in an aqueous silver nitrate solution under visible light irradiation. Annealing under an N2 flow after loading the Co species increased the O2 evolution rate threefold compared to that obtained following conventional annealing under an NH3 flow. Subsequent annealing under an H2 atmosphere exposed the BaTaO2N surface as a result of the aggregation of CoOx particles, and further enhanced the photocatalytic O2 evolution by a factor of two, yielding an apparent quantum efficiency of 0.55% at 420 nm. These results indicate the importance of intimate contact between cocatalyst particles and the photocatalyst, as well as the necessity of exposing the photocatalyst surface to make it available for reduction reactions during photocatalytic water oxidation.
关键词： Cocatalyst,Dispersion,Oxynitride,Visible light
更新于2025-11-19 16:51:07
-
Electric and dielectric characteristics of Al/ZrO2/IL/n-Si MOS capacitors using three-frequency correction method
摘要： In this study, MOS capacitors of Al/ZrO2/IL/n-Si (IL: interface layer) have been fabricated. Bias scan and frequency scan data of measured parallel capacitance (Cm) and parallel resistance (Rm) have been taken in the frequency of ～1 kHz to 2 MHz. To correct external frequency dispersion of parasitic parameters, we have used five-element model (including MOS capacitance C, parallel resistance Rp, IL capacitance Ci, IL resistance Ri, and series resistance Rs) and three-frequency correction method. Extracted capacitance C by the three-frequency correction method has negligible frequency dependence from 0.38 nF to 0.34 nF in the average frequency of ～3.7 kHz to 1.54 MHz. The frequency dispersion of Rp, Ci, Ri, and Rs are explained by some physical mechanisms. Small relative errors ΔC/C, ΔRp/Rp, ΔCi/Ci, ΔRi/Ri and ΔRs/Rs are less than 0.2%, 2%, 3%, 1.2% and 0.4% respectively. We have also used two existing double-frequency methods of three- and four-element models for comparison, and the extracted capacitances show abnormal frequency dependence. Above results indicate the three-frequency method of five-element model is necessary, effective and convenient in providing sufficient list data for bias voltage dependence or frequency dependence. The dielectric parameters, such as relative dielectric constant, conductivity, imaginary part of complex dielectric constant, and dielectric loss tangent have been calculated. The mechanisms of frequency dispersion for the dielectric parameters have been analyzed.
关键词： Three-frequency correction,Parameter extraction,MOS capacitor,Five-element model,Dielectric characteristics,Frequency dispersion
更新于2025-11-14 17:28:48
-
Twins in YAl3(BO3)4 and K2Al2B2O7 Crystals as Revealed by Changes in Optical Activity
摘要： Many borate crystals feature nonlinear optical properties that allow for efficient frequency conversion of common lasers down into the ultraviolet spectrum. Twinning may degrade crystal quality and affect nonlinear optical properties, in particular if crystals are composed of twin domains with opposing polarities. Here, we use measurements of optical activity to demonstrate the existence of inversion twins within single crystals of YAl3(BO3)4 (YAB) and K2Al2B2O7 (KABO). We determine the optical rotatory dispersion of YAB and KABO throughout the visible spectrum using a spectrophotometer with rotatable polarizers. Space-resolved measurements of the optical rotation can be related to the twin structure and give estimates on the extent of twinning. The reported dispersion relations for the rotatory power of YAB and KABO may be used to assess crystal quality and to select twin-free specimens.
关键词： optical activity,inversion twin,YAB,optical rotatory dispersion,KABO,second harmonic generation,frequency conversion,K2Al2B2O7,NLO crystals,YAl3(BO3)4
更新于2025-10-22 19:40:53
-
-edge resonant inelastic x-ray scattering
摘要： We report an Fe L-edge resonant inelastic x-ray scattering (RIXS) study of the unusual superconductor β-FeSe. The high-energy resolution of this RIXS experiment (≈55 meV FWHM) made it possible to resolve low-energy excitations of the Fe 3d manifold. These include a broad peak which shows dispersive trends between 100 and 200 meV along the (π, 0) and (π, π) directions of the one-Fe square reciprocal lattice, and which can be attributed to paramagnon excitations. The multiband valence state of FeSe is among the most metallic in which such excitations have been discerned by soft x-ray RIXS.
关键词： RIXS,β-FeSe,Fe L-edge,dispersion,paramagnon,superconductor,resonant inelastic x-ray scattering
更新于2025-09-23 15:23:52
-
Comparative analysis of capacity oriented Integrated AMI modulation technique for the deployment of radio over fiber system
摘要： To improve the spectral efficiency and to reduce non-linear distortion in the optical system, various advanced modulation techniques have been investigated for radio over fiber (RoF) system. The investigation indicates the high data rate distortion less transmission for long-haul RoF system still further investigation is required to improve spectral efficiency and to get the reduction in signal degradation. In this paper, an advanced modulation technique referred as integrated alternate mark inversion modulation technique based upon external modulation (electro-absorption modulator) has been designed and simulated. The results show better performance in terms of performance metrics i.e. Q-factor (25.15) and BER (4e-140) and also enhance the data transmission capabilities up to 100 Gbps covering the long distance of 250 km resulting a reasonable reduction in signal degradation particularly chromatic dispersion effects for long-haul transmissions.
关键词： Single mode fiber—SMF,Carrier suppressed return to zero—CSRZ,Erbium doped fiber amplifier—EDFA,RoF,Dispersion compensating fiber—DCF,Multi-mode fiber—MMF
更新于2025-09-23 15:23:52
-
Scaling behavior in on-chip field-amplified sample stacking
摘要： Field amplified sample stacking (FASS) uses differential electrophoretic velocity of analyte ions in the high-conductivity background electrolyte zone and low-conductivity sample zone for increasing the analyte concentration. The stacking rate of analyte ions in FASS is limited by molecular diffusion and convective dispersion due to non-uniform electroosmotic flow (EOF). We present a theoretical scaling analysis of stacking dynamics in FASS and its validation with a large set of on-chip sample stacking experiments and numerical simulations. Through scaling analysis, we have identified two stacking regimes that are relevant for on-chip FASS, depending upon whether the broadening of the stacked peak is dominated by axial diffusion or convective dispersion. We show that these two regimes are characterized by distinct length and time scales, based on which we obtain simplified non-dimensional relations for the temporal growth of peak concentration and width in FASS. We first verify the theoretical scaling behavior in diffusion and convection dominated regimes using numerical simulations. Thereafter, we show that the experimental data of temporal growth of peak concentration and width at varying electric fields, conductivity gradients, and EOF exhibit the theoretically predicted scaling behavior. The scaling behavior described in this work provides insights into the effect of varying experimental parameters, such as electric field, conductivity gradient, electroosmotic mobility, and electrophoretic mobility of the analyte on the dynamics of on-chip FASS.
关键词： dispersion,scaling analysis,on-chip electrophoresis,field-amplified sample stacking
更新于2025-09-23 15:23:52
-
A compact leaky-wave antenna using a planar spoof surface plasmon polariton structure
摘要： This article presents and validates a leaky-wave antenna by using the spoof surface plasmon polariton (SSPP) technique. By properly designing the proposed SSPP unit, the SSPP wave can be switched between the confinement and radiation modes. A large radiation efficiency can be achieved by properly designing the modulation depth, which ensures that a compact SSPP leaky-wave array can be realized by using a small number of SSPP radiation units. To verify the design, a prototype which consists of a SSPP feeding network and a 4 by 4 SSPP radiation units has been fabricated by using a low cost FR-4 substrate. A good agreement between simulated and measured results has been obtained. The proposed array antenna shows the promising capability of the SSPP technique for leaky-wave antenna applications.
关键词： dispersion curve,the spoof surface plasmon polariton (SSPP),SSPP antenna array,SSPP power divider
更新于2025-09-23 15:23:52