- 标题
- 摘要
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- 实验方案
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Turbulence-induced optical loss and cross-talk in spatial-mode multiplexed or single-mode free-space communication channels
摘要： Single-mode or mode multiplexed free-space atmospheric optical channels have drawn increasingly more attention in the past decade. The scope of their possible applications spans from the compatibility with the telecom WDM technology, fiber amplifiers, and modal multiplexing for increasing the channel throughput to various quantum communication related primitives such as entanglement distribution, high-dimensional spatially encoded quantum key distribution, and relativistic quantum cryptography. Many research papers discuss application of specific mode sets, such as optical angular momentum modes, for communication in the presence of atmospheric turbulence. At the same time some basic properties and key relations for such channels exposed to the atmospheric turbulence have not been derived yet. In the current paper we present simple analytic expressions and a general framework for assessing probability density functions of channel transmittance as well as modal cross-talk coefficients. Under some basic assumptions the presented results can be directly used for estimation of the Fried parameter of the turbulent channel based on the measured statistics of the fundamental mode transmittance coefficient.
关键词： free-space optical communication,single-mode channels,spatial-mode multiplexing,atmospheric turbulence,quantum communication
更新于2025-09-04 15:30:14
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Ultra-high negative dispersion and nonlinearity based single mode photonic crystal fiber: design and analysis
摘要： In this article, we have proposed a large negative dispersion coef?cient and highly nonlinear polarization maintaining single mode square photonic crystal ?ber. The proposed design is extremely attractive for compensation of chromatic dispersion of - 1052.60 ps/(nm km) to - 2421.90 ps/(nm km) around 1340–1640 nm wavelength band. Guiding characteristics are investigated applying ?nite element method containing perfectly matched layer boundary condition. Simulation outcomes ensure the possibility of large negative dispersion coef?cient and low con?nement loss of - 2015.30 ps/(nm km) and 3.41 9 101 dB/m respectively, at 1550 nm wavelength. The proposed ?ber also exhibits highly nonlinear coef?- cient of 99.73 W-1 km-1 at the same wavelength. Moreover, V parameter assures the single mode operation of the structured ?ber over the whole band of interest. The structural diameter variation of ± 2% over the optimum value is simulated and reported to explore the practical feasibility. Besides, effective area is also presented and explained. From overall investigations, it can be reported that the proposed ?ber will be an attractive candidate in high-speed transmission system for broadband dispersion compensation, nonlinear optics and sensing applications as well.
关键词： Single mode ?ber,Ultra-high negative dispersion,Nonlinear coef?cient,Con?nement loss,Effective area,Dispersion compensating S-PCF
更新于2025-09-04 15:30:14
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Single channel 224 Gbit/s (56-GBaud) PAM-16 transmission using linear digital pre-distortion
摘要： With linear digital pre-distortion (DPD) and 8-bit digital to analogue converter (DAC), a single channel 224 Gbit/s (56-GBaud) 16-level pulse amplitude modulation (PAM-16) signal is experimentally transmitted over a 100 m standard single-mode fibre (SSMF) for the first time using intensity modulation and direct detection (IM/DD). The 3 dB bandwidth of the whole system is around 22 GHz, which is far below the bandwidth of the 56-GBuad PAM-16 signal. The strong inter-symbol interference caused by the limited system bandwidth is pre-compensated by the proposed linear DPD technique. The experimental results indicate that the linear DPD process can effectively avoid the noise enhancement by the aggressive feed-forward equalisation at the receiver, and also improves the system performance at the cost of additional finite impulse response filter at the transmitter.
关键词： linear digital pre-distortion,inter-symbol interference,PAM-16,single-mode fibre,IM/DD
更新于2025-09-04 15:30:14
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Dynamic regulating of single-mode lasing in ZnO microcavity by piezoelectric effect
摘要： Realizing single-mode-lasing output while being able to dynamically select and regulate a specified resonant mode could bring revolutionary impact for laser technology, on-chip data communication, and optical sensing/switches. Here, we demonstrate a single-mode lasing achieved by the piezoresistive and piezoelectric polarization synergistic effect on an epoxy-encapsulated ZnO microresonator. Based on relative shifts of gain spectrum and the resonant wavelength, the lasing mode in a hexagonal ZnO rod can be selected and regulated dynamically within a certain range. The relationship between the corresponding applied strain and the tunable refractive index is analyzed in depth and discussed systematically. Our studies open up exciting avenues for constructing optical mode-phase modulator, high-sensitive optical switches and color-perceived optical sensing.
关键词： optical sensing,ZnO microresonator,single-mode lasing,piezoelectric effect,dynamic regulation
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE Photonics Conference (IPC) - Reston, VA, USA (2018.9.30-2018.10.4)] 2018 IEEE Photonics Conference (IPC) - All-Chalcogenide Single-Mode Couplers
摘要： We demonstrate the fabrication of all-chalcogenide single-mode fiber couplers with a coupling extinction ratio of up to 35 dB. Couplers are made in two formats: wavelength-dependent and polarization beamsplitters with separation of the orthogonally polarized components up to 18 dB.
关键词： polarizing beamsplitter,single-mode coupler,mid-infrared
更新于2025-09-04 15:30:14