共查询到20条相似文献,搜索用时 31 毫秒
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We propose and demonstrate a C-band Erbium-doped fiber amplifier (EDFA) using amplified spontaneous emission (ASE) power peaking-selective
and feedback to achieve highly stabilized and wide dynamic range gain clamping performances. The gain of 16.20 ± 0.13 dB is
obtained with the input signal power dynamic range of 30 dB and the maximum noise figure (NF) was 6.6 dB with the input signal
power from −35 to −10 dBm. To investigate the gain variation for the probe signals, we applied a saturation tone signal to
simulate 16-channel DWDM signals as it is added (dropped) into (from) EDFA. The gain variation of the proposed scheme at a
appropriate ring-cavity loss (VOA = 5 dB) is less than 0.13 dB for the input signal power from −35 to −5 dBm and wavelength
from 1530 to 1564 nm. 相似文献
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The nonlinear effects that limit the performance of the multi-frequency probe(MFP)based coherent optical time domain reflectometry(C-OTDR)are investigated.Based on theoretical analysis and experimental results,compared with conventional C-OTDR,when the probe pulse has power gradient within the pulse width,self-phase modulation(SPM)and cross-phase modulation(XPM)are strengthened in the new C-OTDR scheme.The generation of four-wave mixing(FWM)is dependent on SPM and XPM,and with modulation frequency of phase modulator higher than 40 MHz,the stimulated Brillouin scattering(SBS) threshold can be enhanced by more than 5 dB,which benefits the maximum dynamic range of the MFP C-OTDR. 相似文献
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Kuan Ming Chen 《Optics Communications》2009,282(22):4374-4377
A polymer-dispersed liquid crystal (PDLC)-based variable optical attenuator (VOA) was demonstrated to exhibit a relatively small polarization dependent loss (PDL) in the optical communication C band. The influence of the PDLC characteristics, the temperature, as well as the wavelength of the laser irradiation, on the PDLC VOA performance was analyzed. The PDL, the insertion loss at saturated voltage, and the operating voltage of the PDLC-based VOA were reduced by optimizing the fabrication conditions and applying a bias voltage to the PDLC cells during polymerization-induced phase separation. 相似文献
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A novel scheme of optical power equalization based on Fabry-Perot semiconductor optical amplifier (FPSOA) is proposed. Because of the gain characteristic of FP-SOA, real-time controlling mechanism according to input optical power is aborted in the scheme. The simulations show that 10-dB pulse peak power variation can be clamped in less than i dB. The influences of injecting current, pulse periods, and pulse width are discussed. 相似文献
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We generated pulsed quadrature-squeezed light by cross-phase modulation in single-crystal hexagonal CdSe at wavelengths of 1.4 to 1.55mum . We measured 0.4-dB squeezing (0.7 dB is inferred at the crystal) with 100-fs laser pulses. The wavelength and the intensity dependence, as well as variations in the local oscillator configuration, are examined. At higher intensities squeezing is shown to deteriorate owing to competing nonlinear processes. 相似文献
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A 3-dB paired interference (PI) optical coupler in silicon-on-insulator (SOI) based on rib waveguides with trapezoidal cross section was designed with simulation by a modified finite-difference beam propagation method (FD-BPM) and fabricated by potassium hydroxide (KOH) anisotropic chemical wet etching. Theoretically, tolerances of width, length,and port distance are more than 1, 100, and 1 μm, respectively.Smooth interface was obtained with the propagation loss of 1.1 dB/crn at the wavelength of 1.55μm. The coupler has a good uniformity of 0.2 dB and low excess loss of less than 2 dB. 相似文献
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An InGaAsP/InP waveguide variable optical attenuator (VOA) is proposed in this paper. The device consists of straight input and output waveguides and an S-bend waveguide. An electrode is deposited on a portion of the waveguide to form an active region so that its refractive index can be modified by a current injection, resulting in the variation of the transmitted optical power. The beam propagation method is employed in the numerical simulation and the device structure is optimized using a genetic algorithm. The optimized VOA has a low excess loss (<1 dB) and a large dynamic range of about 40 dB. 相似文献
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Automatic power equalization and stabilization of a liquid crystal enabled channel-selectable optical demultiplexer is demonstrated. The variation among output signals from different channels was reduced from ∼10 dB to 0.15 dB with feedback control. The minimum ripple level of a single channel is ∼0.05 dB. As a variable optical attenuator (VOA), the attenuation range of the device is ∼12.6 dB. 相似文献
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A novel MEMS variable optical attenuator (VOA), which has completely different attenuation mechanism from those in literatures, is proposed and demonstrated in this paper. The basic operation principle is that the optical power coupled between two initially aligned single-mode fibers will be continuously attenuated while the end of one of the fibers is deflected from the initial position. A micromachined solenoid type inductor with a U-shaped permalloy magnetic core is used to attract the deflectable fiber that has a permalloy coat on its end. To fabricate the multi-layer three-dimensional inductive component, a new UV-LIGA process for thick photoresists is developed, combining advantages of both SU-8 and AZ-4000 series photoresists. The inductive component is approximately 1.7 mm×1.3 mm×50μm in size and has a low resistance value (- 2.1Ω). The whole size of the VOA before packaging is 30 mmx2 mmx0.6 mm. The first prototype shows less then 3-dB insertion loss at 0-dB attenuation and nearly 40-dB att 相似文献
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We demonstrate 0.8-dB/cm transmission loss for a single-mode, strip Si/SiO(2) waveguide with submicrometer cross-sectional dimensions. We compare the conventional waveguide-fabrication method with two smoothing technologies that we have developed, oxidation smoothing and anisotropic etching. We observe significant reduction of sidewall roughness with our smoothing technologies, which directly results in reduced scattering losses. The rapid increase in the scattering losses as the waveguide dimension is miniaturized, as seen in conventionally fabricated waveguides, is effectively suppressed in the waveguides made with our smoothing technologies. In the oxidation smoothing case, the loss is reduced from 32 dB/cm for the conventional fabrication method to 0.8 dB/cm for the single-mode waveguide width of 0.5 microm . This is to our knowledge the smallest reported loss for a high-index-difference system such as a Si/SiO(2) strip waveguide. 相似文献
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胡宗福 《中国光学快报(英文版)》2004,2(1)
A new kind of tunable optical filter is proposed for DWDM optical communication application. It is based on cascaded polarization interference filter (PIF). The period and bandpass width of each PIF are decided by its optical path difference between o-ray and e-ray (OPDOE). When their OPDOEs are proportionately designed, the tuning range and bandpass width depend on OPDOE in the first and the last PIF, respectively. The tuning range, bandpass width and crosstalk are independent each other. The crosstalk is related to the OPDOE ratios among PIFs and can be suppressed by designing the PIF's 15 × 2N-7 × l1, 10 × 2N-6 × l1 and 2N-2 × l1 from the first to the last. This suggested OPDOEs can yield -50-dB crosstalk for any tuning range and bandpass width. The insert loss is less than i dB. As its loose alignment requirement, there is no limitation on cascaded PIF number. When 11 PIFs are cascaded, it can achieve 170-nm tuning range, -50-dB crosstalk, bandpass width applicable to 25-GHz channel spacing and 1 dB insert loss. 相似文献
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基于自纠错码的二级脉冲幅度调制与脉冲宽度调制(PWAM)光纤传输技术,对系统中的接收机灵敏度进行了分析.在模拟信号信噪比不小于50 dB,数字信号误码率不低于10-9情况下进行仿真.结果表明,在没有增加系统复杂性的前提下,使用自纠错码时二级脉冲幅度调制以及脉冲调制光纤接收机灵敏度将有1.1 dB的改善. 相似文献
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Avoltage -controlled variabl optical attenuator (VOA) based on silica-b a sed planar ligh t wa ve circu its (P LC) was fabricated by flame hydrolysis deposition (FHD). The variable attenuator with Cr heater achieves 20dB attenuation with 318mW electrical power at 1550 nm. The insertion loss and the polarization dependent loss (PDL) at 0 attenuation are 1dB and 0.23dB, respectively. 相似文献
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研制了一种新型的超小型电磁驱动微机械可调光衰减器(VOA).该器件采用电磁驱动器转动硅基微镜改变光路实现可调衰减,在结构上采用了全磁性回复,完全摆脱了通常的弹性回复造成的部件疲劳、零点偏移等器件重复性问题.驱动电压为0~5 V,工作范围0~40 dB,插入损耗小于0.8 dB,回波损耗小于-50 dB.器件重要部件采用微细电火花加工(EDM)技术制作,并应用FEA软件进行了结构优化,对衰减响应进行了详尽的理论分析.该VOA设计体积仅为25×10×7 mm3,可构成阵列应用于波分复用(WDM/DWDM)系统中各信道的动态信号平衡或网络保护. 相似文献