- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 2019
- higher- order modes
- few-mode regime
- on-board cable systems
- mode coupling
- laser-based multi-Gigabit data transmission
- large core multimode optical fiber
- industrial networks
- differential mode delay
- Optoelectronic Information Science and Engineering
- Povolzhskiy State University of Telecommunications and Informatics (PSUTI)
- Malaviya National Institute of Technology Jaipur
-
Multimode lasing in wave-chaotic semiconductor microlasers
摘要： We investigate experimentally and theoretically the lasing behavior of dielectric microcavity lasers with chaotic ray dynamics. Experiments show multimode lasing for both D-shaped and stadium-shaped wave-chaotic cavities. Theoretical calculations also find multimode lasing for different shapes, sizes, and refractive indices. While there are quantitative differences between the theoretical lasing spectra of the stadium and D-cavity, due to the presence of scarred modes with anomalously high-quality factors, these differences decrease as the system size increases, and are also substantially reduced when the effects of surface roughness are taken into account. Lasing spectra calculations are based on steady-state ab initio laser theory, and indicate that gain competition is not sufficient to result in single-mode lasing in these systems.
关键词： multimode lasing,stadium-shaped cavities,D-shaped cavities,gain competition,wave-chaotic semiconductor microlasers,scarred modes,surface roughness
更新于2025-09-16 10:30:52
-
Multimode dynamics and modeling of free-running and optically injected Fabry-Pérot quantum-dot lasers
摘要： We derive and apply a numerical model for the description of optically injected long-cavity Fabry-Pérot (FP) quantum-dot (QD) lasers, based on a multisection delay-algebraic-equation approach. In conjunction with experimental measurements, we characterize the multimode dynamics of the free-running laser as well as under external optical injection. We investigate the dynamics of the spatial hole burning (SHB) in the charge-carrier distribution, which is signi?cant in QD lasers and is furthermore a driving mechanism for the emergence of multimode dynamics. In the injected laser, we focus on the transition between the locking regions of neighboring FP modes, which could not be described using traditional multimode rate-equation models. For very strong injection, the individual locking cones are found to converge. For intermediate injection strength, an additional dynamic boundary between the unlocked states is found in a narrow dynamical region in between two neighboring locking cones. This region is characterized by a further unlocking of all laser modes. Furthermore, we ?nd the SHB to impose a threshold in the locking strength which must be overcome to lock a laser mode.
关键词： Fabry-Pérot quantum-dot lasers,multimode dynamics,locking regions,spatial hole burning,optical injection
更新于2025-09-16 10:30:52
-
Self-mode-locked multimode lasers for stabilised RF oscillators
摘要： Low phase noise RF oscillator in modern communication systems and opto-electronic oscillator techniques have achieved superior phase noise. Development and characterisation of coupled symmetric multimode multi-section semiconductor laser pairs are reported for building a chip level RF oscillator. The symmetric laser structure operation is adjusted to achieve a self-mode locking of five modes at 26.4 GHz inter-modal oscillation frequency with the phase noise performance of ?92 dBc/Hz at 10 kHz offset frequency.
关键词： self-mode locking,multimode lasers,RF oscillator,opto-electronic oscillator,phase noise
更新于2025-09-16 10:30:52
-
[IEEE 2018 Asia Communications and Photonics Conference (ACP) - Hangzhou, China (2018.10.26-2018.10.29)] 2018 Asia Communications and Photonics Conference (ACP) - Compact 2×2 and 4×4 General Interference Multimode Interferometers Based on Hybrid Plasmonic Waveguide
摘要： We propose 2×2 and 4×4 general MMIs based on hybrid plasmonic waveguides, used for 90° mixers. With the length of 4.57μm/17.5μm for 2×2/4×4 MMI, both MMIs exhibit phase errors below 0.7°, transmission imbalances below 0.6dB.
关键词： Multimode interferometer,Integrated optics device,90° hybrid,Surface plasmon
更新于2025-09-16 10:30:52
-
Sixteen-Pixel NbN Nanowire Single Photon Detector Coupled With 300-??m Fiber
摘要： Niobium nitride (NbN) nanowires have a high repetition rate and efficiency, making them ideal for superconducting nanowire single photon detectors (SNSPDs). However, it is difficult to fabricate NbN arrays over large areas, which is critical for various applications. This paper describes a 4 × 4 NbN SNSPD array (16 pixels) and optical coupling with a 300-μm-diameter multimode fiber using beam compression technology. This is the first NbN SNSPD coupled with such large-diameter fibers. The designed pixels are positioned as closely as possible (pixel filling factor about 98.5%), almost without dead area between them. This results in a system efficiency of 46% and a quantum efficiency of 94.5% for photons (λ = 1064 nm) coupled from multimode fibers. An intrinsic time resolution of less than 69 ps can be obtained. The proposed high-performance single photon detector is suitable for satellite laser ranging. Furthermore, the proposed system is feasible for large SNSPD arrays with NbN, paving the way for the development of efficient photon cameras with NbN nanowires.
关键词： single-photon detector,Multimode fiber,satellite laser ranging,niobium nitride
更新于2025-09-16 10:30:52
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Cost-Effective Snow Removal from Solar Panels
摘要： A conformal permeable toroidal antenna operating in both a vertically polarized monopole mode and circularly polarized (CP) dipole mode in the UHF frequency range is designed based on theory of magneto-dielectric radiators. This antenna has been fabricated using a new advanced ferromagnetic laminate composite material whose high impedance and anisotropic properties enable an antenna that radiates via magnetic currents. The antenna, less than 0.5 m in diameter and less than 2 cm thick, was fabricated and tested. Including the imperfections of the feed network and a simple matching scheme, the antenna operates from 200 to 500 MHz with an input match of better than 10 dB, CP dipole realized gain as high as 2 dBi, and monopole mode vertically polarized gain as high as 1 dBi.
关键词： ferromagnetic materials,wideband antenna,multimode antenna,multifunction antenna,Conformal antennas
更新于2025-09-16 10:30:52
-
In-Parallel Polar Monitoring of Chemiluminescence Emission Anisotropy at the Solida??Liquid Interface by an Optical Fiber Radial Array
摘要： Chemiluminescence (CL) detection is widely employed in biosensors and miniaturized analytical devices since it offers high detectability and flexible device design (there are no geometry requirements for the measurement cell, except the ability to collect the largest fraction of emitted photons). Although the emission anisotropy phenomenon for an emitting dipole bound to the interface between two media with different refractive index is well known for fluorescence, it is still poorly investigated for CL reactions, in which the excited-state reaction products can diffuse in solution before the photon emission event. In this paper, we propose a simple method for the real-time evaluation of the CL emission anisotropy based on a radial array of optical fibers, embedded in a poly(methyl methacrylate) semicylinder and coupled with a Charge-Coupled Device (CCD) camera through a suitable interface. The polar-time evolutions of the CL emission have been studied for catalyzing enzymes immobilized onto a solid surface (heterogeneous configuration) or free in solution (homogeneous configuration). Evidence of the anisotropy phenomenon is observed, indicating that the lifetime of the excited-state products of the enzyme-catalyzed reactions is shorter than the time required for their diffusion in solution at a distance at which the CL can be considered isotropic. These results open new perspectives in the development of CL-based miniaturized analytical devices.
关键词： CCD camera detector,chemiluminescence,emission anisotropy,multimode optical fiber
更新于2025-09-16 10:30:52
-
Design and Characterization of Surface Relief Grating on Etched Multimode Optical Fiber For Refractive Index Sensing
摘要： We report a simple and compact optical fiber sensor based on surface relief gratings in conventional graded-index multimode optical fiber (GIMMF) for refractive index sensing. Bragg gratings on MMF are less explored compared to its single mode counterpart, even though the MMF platform possesses several advantages such as robustness, enhanced light-matter interaction and easy light coupling. In this work, surface relief gratings are directly written on one side of the cladding etched MMF core surface by using focused ion beam milling (FIB). A detailed theoretical analysis of the structure and sensing principle is analysed. The device performance as a refractive index sensor has been investigated experimentally by immersing the device in different concentration of NaCl solution. Experimental results show a sensitivity of 70 nm/RIU for a refractive index range of 1.333 to 1.345. The device is easy to fabricate with high repeatability and low cost, compactness in design and competent to be used in harsh environmental conditions. The surface grating on etched MMF provides a better interaction between the sensing region and the environment which makes it a potential candidate for various chemical and biological sensing applications.
关键词： optical fiber sensor,refractive index sensor,Multimode optical fiber grating,optical fiber micro-machining
更新于2025-09-16 10:30:52
-
Demonstration of photona??photon resonance peak enhancement by waveguide configuration modification on active multimode interferometer laser diode
摘要： The recent rapid growth of data traffic is leading to high-speed communication for local areas, such as the fiber-to-the-home service. A semiconductor laser is used for such a purpose; however, there is the difficulty that an even higher frequency response occurs in only carrier-photon resonance. For this reason, it is effective to use a second resonance, such as a photon–photon resonance (PPR), for enhancing the frequency response, and the active multimode interferometer laser diode (active-MMI LD) is one of the candidates for achieving a high PPR frequency. In order to obtain an even higher PPR frequency, we have investigated the control scheme of enhancing PPR. In this work, we compared two types of active-MMI waveguide structures to confirm the scheme. As a result, a 3.8 GHz enhancement of the PPR peak, resulting in a 3 dB lower frequency response of 17 GHz, has been successfully achieved by waveguide geometry modification.
关键词： high-speed communication,waveguide configuration,active multimode interferometer laser diode,photon–photon resonance
更新于2025-09-16 10:30:52
-
Simple intra-cavity beam shaping for generating a shape-invariant flat-top laser beam
摘要： Simple intra-cavity beam shaping for generating a shape-invariant flat-top laser beam
关键词： shape invariant beam,transverse modes,beam shaping,multimode laser,flat-top
更新于2025-09-16 10:30:52