- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
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
-
Enhancement of Signals Characteristics with Least Effect of Optical Communication Losses for Dense Optical Communication Systems
摘要： In this paper, the major aim is to enhance the bandwidth and therefore increase the capacity of the optical fibre communication system by reducing the dispersion in the fibre. Dispersion compensation is necessary to reduce losses and cost of the system. In this paper, we are basically focusing on reducing or decreasing chromatic dispersion. Chromatic dispersion is a type of dispersion in which pulse broadening occurs due to delay in different spectral components. We here make use of dispersion compensated fibre (DCF) for reducing the dispersion in the WDM system. Here, we basically use three dispersion compensated techniques (pre-compensation, post-compensation and mix compensation). The comparison in the three models of dispersion compensated technique is made in terms of transmission power vs. Q factor and also transmission power vs. Bit Error Rate.
关键词： DCF,MMF,WDM,SMF,quality factor,BER,optical amplifier
更新于2025-09-12 10:27:22
-
Suppressing Dark Counts of Multimode-Fiber-Coupled Superconducting Nanowire Single-Photon Detector
摘要： Large active-area superconducting nanowire single-photon detectors (SNSPDs) coupled with multimode fibers (MMFs) can provide high light-gathering capacity, which is essential for free-space detection applications in photon-starved regimes. However, MMF-coupled SNSPDs often suffer from large system dark count rates (DCRsys) over kHz due to blackbody radiation of the MMF at room temperature. Such large DCRsys would significantly degrade signal-to-noise ratio (SNR) of the receiving system. This paper reports an MMF-coupled large-active-area SNSPD system with low DCRsys by using a homemade cryogenic MMF filter bench. The filter bench, which consists of lenses and optical filters, can provide a high transmittance of about 80% at the central wavelength of the passband (1550 ± 12.5 nm) and a wide blocking range from 500 nm to over 6000 nm at 40 K. With using the filter bench, the DCRsys of an MMF-coupled 9-pixel SNSPD array with an active area of 50 μm in diameter is greatly suppressed by 23 dB with 1 dB loss of system detection efficiency (SDE). The detector demonstrates an SDE of 51% at a DCRsys of 100 Hz for 1550 nm photons. Thus, SNR of the detector is enhanced by about 160 times and the noise equivalent power is improved to 3×10?19 W/Hz1/2.
关键词： cryogenic MMF filter bench,multimode fibers (MMFs),Superconducting nanowire single-photon detectors (SNSPDs),dark count rates (DCRsys),signal-to-noise ratio (SNR)
更新于2025-09-11 14:15:04
-
[IEEE 2018 International Conference on Wireless Communications, Signal Processing and Networking (WiSPNET) - Chennai, India (2018.3.22-2018.3.24)] 2018 International Conference on Wireless Communications, Signal Processing and Networking (WiSPNET) - Integration of Visible Light Communication and Fiber Communication System
摘要： In this paper, we present an integrated fiber and visible light communication (VLC) system with both single and multimode fibers. Before establishing the fiber–VLC link, we implement a fiber link alone and achieve least BER for a particular length of the fiber. This fiber length is taken as an optimum performing link. The main performance measure utilized in this paper is the Bit Error Rate (BER). Optimum performance is achieved at the point of minimum BER. For an optimum performing fiber–VLC link, the dispersion is analyzed and the compensation of chromatic dispersion is done using ideal dispersion compensation Fiber Bragg Grating (FBG). Utilizing the Gray coded input sequence instead of direct binary sequence reduces the BER, since adjacent constellation points will only differ in one bit. The BER results for 16 QAM (Quadrature Amplitude Modulation) and 64 QAM using Orthogonal Frequency Division Multiplexing (OFDM) are compared for both single mode fiber and multimode fiber links. The simulation results show that for Single Mode Fiber–VLC (SMF–VLC) link the dispersion compensation is better when compared to the Multi Mode Fiber–VLC (MMF–VLC) link.
关键词： Dispersion Compensation FBG,BER,fiber–VLC link,Gray coded input,SMF–VLC,MMF–VLC
更新于2025-09-09 09:28:46