修车大队一品楼qm论坛51一品茶楼论坛,栖凤楼品茶全国楼凤app软件 ,栖凤阁全国论坛入口,广州百花丛bhc论坛杭州百花坊妃子阁

oe1(光电查) - 科学论文

过滤筛选

出版时间
  • 2019
研究主题
  • Distributed optical fiber sensing
  • Optical frequency domain reflection
  • Polynomial regression algorithm
  • Nonlinear tuning compensation
应用领域
  • Optoelectronic Information Science and Engineering
机构单位
  • Hebei University of Technology
777 条数据
?? 中文（中国） ▾

  • Carboxyl graphene oxide solution saturable absorber for femtosecond mode-locked erbium-doped fiber laser

    摘要： The carboxyl-functionalized graphene oxide (GO-COOH) is a kind of unique two-dimensional (2D) material and possesses excellent nonlinear saturable absorption property and high water-solubility. In this paper, we prepare saturable absorber (SA) device by depositing GO-COOH nanosheets aqueous solution on a D-shaped ?ber. The modulation depth (MD) and saturable intensity of the SA are measured to be 9.6% and 19 MW/cm2, respectively. By inserting the SA into the erbium-doped ?ber (EDF) laser, a passively mode-locked EDF laser has been achieved with the spectrum center wavelength of 1562.76 nm. The pulse duration, repetition rate, and the signal-to-noise ratio (SNR) are 500 fs, 14.79 MHz, and 80 dB, respectively. The maximum average output power is measured to be 3.85 mW. These results indicate that the GO-COOH nanosheets SA can be used as a promising mode locker for the generation of ultrashort pulses.

    关键词： nonlinear optical materials,mode-locked pulse,?ber lasers,carboxyl graphene oxide

    更新于2025-11-28 14:24:03

  • Self-starting mode-locked Tm-doped fiber laser using a hybrid structure of no core - graded index multimode fiber as the saturable absorber

    摘要： We experimentally demonstrated a passively mode-locked all-fiber Tm laser using a no-core-graded-index multimode fiber structure as a saturable absorber based on the nonlinear multimode interference. Stable fundamentally mode-locking operation was obtained at a pump threshold of 180 mW. The output soliton pulses had a centre wavelength, spectral width, pulse duration, and repetition rate of 1895.7 nm, 3.3 nm, 1.25 ps, and 18.91 MHz, respectively. This is a simple, low-cost, stable, and convenient laser oscillator, with many potential applications in eye-safe ultrafast photonics.

    关键词： Nonlinear multimode interference,Fiber laser,Mode-locked laser

    更新于2025-11-28 14:24:03

  • Multiplexed ultrafast fiber laser emitting multi-state solitons

    摘要： Ultrafast fiber lasers have been serving as an ideal playground for spreading the extensive industrial applications and exploring the optics nonlinear dynamics. Here, we report a bidirectional fiber laser scheme for validating the possibility of a multiplexed laser system, which is passively mode-locked by the nonlinear polarization rotation (NPR) technique. In particular, the proposed fiber laser consists of one main cavity and two counter-propagating branches with different dispersion distributions. Thus, different formation mechanisms are introduced into the lasing oscillator. Consequently, stable conventional solitons (CSs) and dissipative solitons (DSs) are respectively formed in the clockwise (CW) and counterclockwise (CCW) directions of the same lasing oscillator. Moreover, attributing to the strong birefringence filtering effect, the wavelength selection mechanism is induced. Through the proper management of intra-cavity birefringence, wideband wavelength tuning and switchable multi-wavelength operations are experimentally observed. The central wavelength of CS can be continuously tuned from 1560 nm to 1602 nm. Additionally, the evolution process of different multi-wavelength operations is also elucidated. Benefiting from this multiplexed laser scheme, bidirectional lasing oscillation, multi-state soliton emission, wavelength tuning and multi-wavelength operations are synchronously realized in a single laser cavity. To the best of our knowledge, it is the first time for such a multiplexed fiber laser has been reported. The results provide information for multifunctional ultrafast fiber laser system, which is potentially set for telecommunications, fiber sensing and optics signal processing, etc.

    关键词： multi-wavelength operations,nonlinear polarization rotation,wavelength tuning,Ultrafast fiber lasers,dissipative solitons,conventional solitons

    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

  • L-band tunable and dual-wavelength mode locked fiber laser with NCF-GIMF based SA

    摘要： A hybrid structure of no-core fiber and graded-index multimode fiber (NCF-GIMF) is demonstrated, which can be used as both the saturable absorber (SA) and the wavelength selective element. By employing such a device, an L-band wavelength tunable Er-doped mode-locked laser is realized and stable single solitons of ~1.7ps, with continuously tunable wavelengths from 1574 nm to 1601.1 nm, are generated. Moreover, dual-wavelength mode-locked laser operation at 1575.4 nm and 1603 nm is achieved, with pulse duration of 1.2 ps and 1.7 ps, respectively. The proposed device is simple and compact, and represents an effective approach for tunable and dual-wavelength mode-locked fiber laser operation.

    关键词： Laser tuning,Optical fiber devices,Laser mode locking,Fiber-graded index multimode fiber,Fiber nonlinear optics

    更新于2025-11-28 14:23:57

  • Enhanced optical Kerr nonlinearity of graphene/Si hybrid waveguide

    摘要： In this work, we experimentally study the optical Kerr nonlinearities of graphene/Si hybrid waveguides with enhanced self-phase modulation. In the case of CMOS compatible materials for nonlinear optical signal processing, Si and silicon nitride waveguides have been extensively investigated over the past decade. However, Si waveguides exhibit strong two-photon absorption (TPA) at telecommunication wavelengths, which leads to a signi?cant reduction of the nonlinear ?gure-of-merit (FOM). In contrast, a silicon nitride based material system usually suppresses the TPA but simultaneously leads to the reduction of Kerr nonlinearity by one order of magnitude. Here, we introduce a graphene/Si hybrid waveguide, which maintains the optical properties and CMOS compatibility of Si waveguides, while enhancing the Kerr nonlinearity, by transferring over to the top of the waveguides. The graphene/Si waveguides are measured to have an enhanced nonlinear parameter of 510 W(cid:2)1 m(cid:2)1, compared with that of the Si waveguide of 150 W(cid:2)1 m(cid:2)1. An enhanced nonlinear FOM of 2.48 6 0.25 has been achieved, which is four times larger than that of the Si waveguide of 0.6 6 0.1. This work reveals the potential application of graphene/Si hybrid waveguides with high Kerr nonlinearity and FOM for nonlinear all-optical signal processing.

    关键词： nonlinear all-optical signal processing,graphene/Si hybrid waveguide,optical Kerr nonlinearity,CMOS compatible,self-phase modulation

    更新于2025-11-28 14:23:57

  • Supercontinuum generation of highly nonlinear fibers pumped by $1.57$-${\rm{\mu }}{\rm{m}}$ laser soliton

    摘要： Highly nonlinear ?bers (HNLFs) are crucial components for supercontinuum (SC) generation with laser solution. However, it is dif?cult to exactly estimate the structure of produced SC according to material parameters. To give a guideline for choosing and using HNLFs for erbium-?ber-based optical applications, we demonstrate SC generation in ?ve types of HNLFs pumped by 1.57-μm laser solitons. All ?ve ?bers output a SC exceeding 1000 nm. Three different SC formation processes were observed in the experiment. By comparing optical parameters of these ?bers, we ?nd the zero dispersion wavelength (ZDW) of ?ber has an important in?uence on the SC structure and energy distribution for a given pump source.

    关键词： highly nonlinear ?ber,erbium-?ber laser,supercontinuum generation

    更新于2025-11-28 14:23:57

  • [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

  • Three-Dimensional Segmentation and Quantitative Measurement of the Aqueous Outflow System of Intact Mouse Eyes Based on Spectral Two-Photon Microscopy Techniques

    摘要： PURPOSE. To visualize and quantify the three-dimensional (3D) spatial relationships of the structures of the aqueous outflow system (AOS) within intact enucleated mouse eyes using spectral two-photon microscopy (TPM) techniques. METHODS. Spectral TPM, including two-photon autofluorescence (TPAF) and second-harmonic generation (SHG), were used to image the small structures of the AOS within the limbal region of freshly enucleated mouse eyes. Long infrared excitation wavelengths (930 nm) were used to reduce optical scattering and autofluorescent background. Image stacks were collected for 3D image rendering and structural segmentation. For anatomical reference, vascular perfusion with fluorescent-conjugated dextran (150 KDa) and trans-corneal perfusion with 0.1 lm fluorescent polystyrene beads were separately performed to identify the episcleral veins (EV) and the trabecular meshwork (TM) and Schlemm's canal (SC), respectively. RESULTS. Three-dimensional rendering and segmentation of spectral two-photon images revealed detailed structures of the AOS, including SC, collector channels (CC), and aqueous veins (AV). The collagen of the TM was detected proximal to SC. The long and short axes of the SC were 82.2 ± 22.2 μm and 6.7 ± 1.4 μm. The diameters of the CC averaged 25.6 ± 7.9 μm where they originated from the SC (ostia), enlarged to 34.1 ± 13.1 μm at the midpoint, and narrowed to 18.3 ± 4.8 μm at the junction of the AV. The diameter of the AV averaged 12.5 ± 3.4 μm. CONCLUSIONS. Spectral TPM can be used to reconstruct and measure the spatial relationships of both large and small AOS structures, which will allow for better understanding of distal aqueous outflow dynamics.

    关键词： second-harmonic generation,aqueous outflow,nonlinear microscopy,glaucoma,two-photon fluorescence microscopy

    更新于2025-11-21 11:08:12

  • Optimized signal-to-noise ratio with shot noise limited detection in Stimulated Raman Scattering microscopy

    摘要： We describe our set-up for Stimulated Raman Scattering (SRS) microscopy with shot noise limited detection for a broad window of biologically relevant laser powers. This set-up is used to demonstrate that the highest signal-to-noise ratio (SNR) in SRS with shot noise limited detection is achieved with a time-averaged laser power ratio of 1:2 of the unmodulated and modulated beam. In SRS, two different coloured laser beams are incident on a sample. If the energy difference between them matches a molecular vibration of a molecule, energy can be transferred from one beam to the other. By applying amplitude modulation to one of the beams, the modulation transfer to the other beam can be measured. The efficiency of this process is a direct measure for the number of molecules of interest in the focal volume. Combined with laser scanning microscopy, this technique allows for fast and sensitive imaging with sub-micrometre resolution. Recent technological advances have resulted in an improvement of the sensitivity of SRS applications, but few show shot noise limited detection. The dominant noise source in this SRS microscope is the shot noise of the unmodulated, detected beam. Under the assumption that photodamage is linear with the total laser power, the optimal SNR shifts away from equal beam powers, where the most signal is generated, to a 1:2 power ratio. Under these conditions the SNR is maximized and the total laser power that could induce photodamage is minimized. Compared to using a 1:1 laser power ratio, we show improved image quality and a signal-to-noise ratio improvement of 8 % in polystyrene beads and C. Elegans worms. Including a non-linear damage mechanism in the analysis, we find that the optimal power ratio converges to a 1:1 ratio with increasing order of the non-linear damage mechanism.

    关键词： shot noise limited detection,signal-to-noise ratio,Nonlinear Raman microscopy

    更新于2025-11-21 11:08:12