GLORIA

GEOMAR Library Ocean Research Information Access

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (1,724)
  • 1
    facet.materialart.
    Unknown
    Institute of Electrical and Electronics Engineers (IEEE)
    Publication Date: 2018-04-07
    Description: A 128 Gbit/s free-space laser link demonstration has been presented. We use a simulated atmosphere system with a tunable 1 km equivalent weak turbulence channel. Eye diagrams and constellation diagrams were observed. Bit error rate curves of back to back transmission and that in a simulated atmospheric channel are measured. The results show that the receiving sensitivities can be better than –37.3 dBm at the rate of 128 Gbit/s in a turbulence channel. To the best of our knowledge, it is the first time that the transmission performance of high speed space laser in a tunable atmospheric channel is studied.
    Electronic ISSN: 1943-0655
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2018-04-07
    Description: An efficient method based on a hybrid approach that combines extreme learning machine (ELM) technique and differential evolution (DE) algorithm is proposed to optimize the multipumped Raman fiber amplifier (RFA). The proposed method takes advantage of the fast learning speed and high generalization of the ELM as well as the strong global search capability of DE. From a novel perspective, we utilize ELM as a powerful learning tool to construct the nonlinear mapping between the pump parameters and gains of RFA. Instead of time-consuming integration of Raman coupled equations, the gains can be directly and accurately determined by the ELM model. To obtain a flat gain spectrum, DE algorithm is employed to find the optimal wavelengths and powers of pumps. The well-trained ELM model is incorporated into the evolution of DE to accelerate the search process. The results show that the designed RFAs with the optimized pump parameters achieve the desired gain performance and meanwhile maintain very low level of gain ripple. In comparison to other related methods, the proposed method significantly shortens the computation time and enhances the overall optimization efficiency, which offers potential for real-time adjustment and flexibility of RFA design.
    Electronic ISSN: 1943-0655
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    facet.materialart.
    Unknown
    Institute of Electrical and Electronics Engineers (IEEE)
    Publication Date: 2018-04-07
    Description: We numerically report designs of color filters comprising of 2-D photonic crystal (2D-PhC) slabs of square lattice of air holes. The filter principle is based on excited Fano-like guided-mode resonances (GMRs) in the visible regime with high-quality factor ( Q -factor) and low reflection sidebands. The 2D-PhC slab architecture influence on its spectroscopic property is comprehensively investigated. We introduce an alternative PhC lattice, which is formed by introducing an additional hole in each unit cell to enhance the light confinement in the waveguide slab, as such the induced Fano-like GMRs’ Q -factor is significantly increased about two orders of magnitude compared to the traditional PhC without additional holes. At Fano-like GMRs, two in-plane waves oscillate toward the opposite directions with a phase difference of π . The radiated fields of these waves strongly cancel each other in the far field, and the coupling between the waveguiding slab and the incident light is dramatically reduced resulting in the high Q -factor of the Fano-like GMR in the introduced PhC slab. As a result, the 2D-PhC slab excited Fano-like GMRs in this work may find fascinating applications in optical filters, optical imaging, optical switching, and so on.
    Electronic ISSN: 1943-0655
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    facet.materialart.
    Unknown
    Institute of Electrical and Electronics Engineers (IEEE)
    Publication Date: 2018-04-07
    Description: The paper introduces a 24-channel air-trench isolated Silica-based VOA array. The air trenches thermally insulate the VOAs with etched-free waveguide technologies. Reactive ion etching and wet etching were used at different channel locations to suppress thermal crosstalk and reduce power consumption. When thermal crosstalk is declined by 3 dB for the straight waveguide, the power consumption was decreased from 195 to 95 mW because the lightwave radiation can be scattered by the air trench in the dark state. This crosstalk is improved by 9 dB for the curved waveguide. The polarization dependent loss falls down to 0.28 dB at 15 dB attenuation since the air trench and etched-free waveguide also releases the stress.
    Electronic ISSN: 1943-0655
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2018-04-07
    Description: The improved performance of Si quantum dot-based silicon nitride light-emitting devices with the inserted hole-blocking nc-Si layer was investigated. An enhanced electroluminescence (EL) efficiency of 200% from the SiN x -based LEDs is demonstrated through H 2 plasma treatment of the inserted nc-Si layer. The enhancement of an EL efficiency is depended on time for plasma treatment. Moreover, the injected current of the devices with H 2 plasma treatment is significantly higher than that of the device without H 2 plasma treatment under the same driving voltage. The Z-parameter of the devices increases from 1.25 to 1.41 after H 2 plasma treatment of inserted nc-Si layer. The inserted nc-Si layers with and without H 2 plasma treatment were further investigated by the Raman spectroscopy and the Fourier transform infrared absorption spectroscopy, respectively. It is suggested that the improved EL efficiency is due to the suppression of nonradiative recombination, which resulted from the hydrogen passivation that effectively reducing Si-related defect states of the inserted nc-Si layer.
    Electronic ISSN: 1943-0655
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    facet.materialart.
    Unknown
    Institute of Electrical and Electronics Engineers (IEEE)
    Publication Date: 2018-04-04
    Description: We report on the lasing action in weakly modulated parity-time (PT) symmetric lattices. At the exceptional point in PT-symmetric lattices, the amplitude and phase of unidirectionally scattered waves are independently and flexibly determined by the PT modulations, thus, providing a distinctive route to construct a lasing mode in finite systems with weakly modulated structures. It is revealed that the resonant feedback mechanism plays a crucial role in building up the lasing action. Our finding would enrich the singularity dynamics in the weakly modulated PT systems.
    Electronic ISSN: 1943-0655
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2018-04-04
    Description: A secure key distribution scheme for orthogonal frequency division multiplexing (OFDM) passive optical network system is proposed and experimentally demonstrated. The training symbol (TS), which is used for time synchronization and channel estimation, is formed by adopting a noise-like chaotic sequence. The redundancy of the TS is utilized to embed secure keys. An experiment is performed, in which 7.64 Gb/s 16-quadrature-amplitude-modulation OFDM data and 28.4 Mb/s keys embedded in are successfully transmitted over 25 km standard single mode fiber. The results indicate a promising key distribution method for physical layer secure optical communication.
    Electronic ISSN: 1943-0655
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2018-04-04
    Description: We report a self-injection-locked InAs/InP quantum-dash tunable laser with ∼11 nm (∼1602–1613 nm) tuning window for next generation multiuser ultrahigh capacity fiber/free-space optics (FSO)/hybrid fiber-FSO-based optical networks. A tunability of >18 independently locked subcarriers with ∼28 dB side mode suppression ratio (SMSR) and stable (±0.1 dBm) mode power is exhibited, and an estimated small injection ratio of ∼–22 dBm is found to sustain locking and SMSR. Error free transmission of 100 and 128 Gb/s externally modulated dual-polarization quadrature phase shift keying (DP-QPSK) signals over 20 km single mode fiber (SMF) and 16 m indoor FSO links are demonstrated across 8 and 4 individual subcarriers, respectively, thus covering the entire tuning range. Moreover, up to 168 (192) Gb/s successful transmission over 10 km SMF (BTB) and 176 Gb/s over 16 m FSO link is achieved on a ∼1610 nm subcarrier. Finally, a 128 Gb/s DP-QPSK transmission over 11 km SMF–8 m FSO–11 km SMF hybrid system is accomplished, thus paving the potential deployment of this single-chip, cost-effective, and energy efficient tunable light source in terabits/s next-generation passive optical networks.
    Electronic ISSN: 1943-0655
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    facet.materialart.
    Unknown
    Institute of Electrical and Electronics Engineers (IEEE)
    Publication Date: 2018-04-04
    Description: A three-dimensional dual-band perfect absorber in the THz range (3–10 THz) is theoretically investigated. The absorber is composed of periodically placed cross- and disk-shaped graphene arrays on the top of a gold layer separated by a thick SiO $_{2}$ dielectric spacer. The simulated results show two absorption peaks with near-unity absorbance ( $99.923%$ and $99.601%$ ) at wavelengths 43.747  $mu$ m and 69.94  $mu$ m, respectively. Also, the absorber is insensitive to the polarization of the incident light and has a good tolerance to the incident angle whether it is TE or TM waves. Moreover, the peak wavelengths of the absorber can be flexibly modulated by varying the Fermi level $mu _{C}$ of graphene while no need to refabricate the structure. This paper provides a new perspective for the design of graphene-based tunable multiband perfect THz absorbers, but not limited to THz absorbers, and may also be used in other THz graphene-based photonic devices.
    Electronic ISSN: 1943-0655
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    facet.materialart.
    Unknown
    Institute of Electrical and Electronics Engineers (IEEE)
    Publication Date: 2018-04-04
    Description: We propose a method of computational temporal ghost imaging over a single optical fiber using simple optical intensity detection instead of coherent detection. The transfer function of a temporal ghost imaging system over a single optical fiber is derived, which is a function of the total fiber dispersion and the power density spectrum of the light source. In the simulations, we find that the bandwidth of the transfer function will decrease rapidly along with the increase of fiber length or light source bandwidth, resulting in a significantly distorted ghost image. To improve the image quality, we first calculate the transfer function by approximating the optical spectrum of the light source based on intensity detection as its power density spectrum. Then, we use an optimized Fourier deconvolution to compute a high-quality image by deconvoluting the measured transfer function from the spectrum of the distorted image. Our experiments achieve single-arm ghost images of a 5-Gb/s nonreturn-to-zero pulse object over a 200-km fiber, which have almost the same quality as the two-arm ones.
    Electronic ISSN: 1943-0655
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...