共查询到20条相似文献,搜索用时 15 毫秒
1.
提出了解复用窗口匹配滤波器的概念,分析了利用光带通滤波器提高光时分复用(OTDM)频谱效率的光谱压缩技术。基于自制的40Gb/sOTDM复用器,采用电吸收调制器(EAM)及时钟提取模块组成的反馈环路解复用模块,以阵列波导光栅(AWG)作为电吸收采样窗口(EASW)的匹配滤波器对4×10Gbit/sOTDM信号进行光谱压缩,实现了无误码传输100km及传输后的解复用。实验结果表明,AWG的使用使得OTDM信号的频谱效率提高至4倍。 相似文献
2.
《Photonics Technology Letters, IEEE》2007,19(19):1454-1456
We propose a novel hybrid optical time-division multiplexing (OTDM) approach, which contains hybrid modulation formats of return-to-zero on-off keying and return-to-zero differential-phase-shift keying, and investigate its demultiplexing performance. Compared with conventional OTDM with homogenous modulation format, the target demultiplexed channel in a hybrid OTDM signal suffers from much less degradation due to the possible crosstalk from the adjacent channels. We experimentally demonstrate 84.88- to 10.61-Gb/s hybrid OTDM demultiplexing and achieve a relatively wide switching window, which cannot be realized by using the conventional OTDM. Moreover, experimental results at 42.44 Gb/s show a much larger tolerance against timing misalignment in demultiplexing, which further validates the improved demultiplexing performance by using the hybrid OTDM scheme. 相似文献
3.
Nakamura S. Ueno Y. Tajima K. Sasaki J. Sugimoto T. Kato T. Shimoda T. Itoh M. Hatakeyama H. Tamanuki T. Sasaki T. 《Photonics Technology Letters, IEEE》2000,12(4):425-427
We have developed a hybrid-integrated symmetric Mach-Zehnder all-optical switch and evaluated the demultiplexing of 168-Gb/s data pulses at a repetition rate of 10 GHz with this switch. A compact, stable device was realized by assembling semiconductor optical amplifiers as nonlinear waveguides on a planar lightwave circuit in a self-aligned manner. A 6.0-ps switching window needed for 168-Gb/s demultiplexing was provided by the push-pull operation of the symmetric Mach-Zehnder all-optical switch. Demultiplexed signal light showed a high extinction ratio of better than 18 dB. Error-free demultiplexing with a bit error rate of 10-11 was achieved 相似文献
4.
Toward a 100-Gsample/s photonic A-D converter 总被引:2,自引:0,他引:2
We propose a 100-Gsample-per-second (GSPS) real time photonic analog-to-digital converter architecture and demonstrate the 100-GSPS photonic sampling and 1:8 time-division optical demultiplexing required to implement such a converter. The high-speed demultiplexing is achieved with a lithium niobate intensity modulator-based serial-parallel converter. Experimental results are presented indicating the potential for >4-bit performance in a fully implemented analog-to-digital conversion system 相似文献
5.
Uchiyama K. Morioka T. Kawanishi S. Takara H. Saruwatari M. 《Lightwave Technology, Journal of》1997,15(2):194-201
This paper investigates experimentally and theoretically the signal-to-noise ratio (SNR) characteristics of 100 Gb/s all-optical demultiplexing using a nonlinear optical loop mirror (NOLM). The analysis takes into account two effects that degrade the SNR associated with NOLM demultiplexing. First is channel crosstalk originating from the leakage of nontarget channels. Second is the intensity fluctuations of demultiplexed signals caused by the combined effects of timing jitter and a profile of the switching window. Considering these two effects, power penalties associated with NOLM. Demultiplexing are theoretically evaluated using the conventional noise theory of an optical receiver followed by an optical preamplifier. Experimental results of bit error rate measurements for 100 Gb/s demultiplexing using three different NOLMs with different intrinsic crosstalk values, defined by signal transmittance in the absence of control pulses, show that the power penalties are in good agreement with the evaluation based upon our proposed analysis. It can be found from our investigation in demultiplexing from 100 to 10 Gb/s that intrinsic crosstalk of less than -25 dB, corresponding to a coupling ratio, K, of |K-0.5|⩽0.03, is required for the power penalty of less than 1 dB. The root-mean-square (rms) value of the relative timing jitter necessary for obtaining a sufficient timing tolerance width for combining control and signal pulses is determined 相似文献
6.
Parolari P. Boffi P. Marazzi L. Martinelli M. 《Lightwave Technology, Journal of》2003,21(8):1808-1812
Cascading a semiconductor optical amplifier (SOA)-based Sagnac interferometer with a second Sagnac stage allows significant improvement in the overall demultiplexer performance. A theoretical analysis and simulations show that the exploitation of a two-stage architecture results in a demultiplexing window sharpness and time compression. Eye-diagram and Q-factor experimental characterization at 2.5 Gb/s of the demultiplexer is presented, showing a 25% compression in time of the two-stage switching window and a 4.7 Q-factor improvement. 相似文献
7.
Schubert C. Diez S. Berger J. Ludwig R. Feiste U. Weber H.G. Toptchiyski G. Petermann K. Krajinovic V. 《Photonics Technology Letters, IEEE》2001,13(5):475-477
We report on an all-optical demultiplexer based on gain-transparent operation of a semiconductor optical amplifier (SOA) in an ultrafast-nonlinear interferometer (GT-UNI). The GT-UNI comprises a robust fiber-chip setup in a folded geometry. For switching window widths of 5.2 ps and 6.0 ps, error-free demultiplexing of 160-10 Gb/s is demonstrated 相似文献
8.
9.
All-optical time-division demultiplexing using a nonlinear fiber Sagnac interferometer switch (NSIS) is studied with respect to the two main causes that degrade the bit-error-rate (BER) performance: crosstalk and timing jitter. It is shown that unwanted cross-phase-modulation in the reference signal which counter-propagates to the control pulse, as well as the poor extinction of the switch itself, seriously degrades the extinction ratio of the switch, thus increasing the crosstalk from other channels. Numerical calculations clarify the effect of the switching window width, window shape, and the multiplexed channel number on the power penalty in terms of BER performance. Timing jitter between the signal and control pulses is investigated as another degradation factor that causes an error floor in BER performance. It is found that the minimum BER is obtained when the window width is set to the time slot width and the rms value of the jitter must be less than 1/14.1 times the time slot width to ensure that BER<10-12. To confirm this analysis, precise measurements of BER performance with NSIS-based demultiplexing are performed using amplified gain-switched laser diode pulses, as the relative timing jitter, switching window width, and multiplexed channel number are varied. Good agreement with the analysis is shown. Finally, optimum system design based on a small power penalty and low error floor is described. It is shown that the NSIS has the potential of demultiplexing a 160-Gb/s or 320-Gb/s optical data stream into its 40-Gb/s constituents with only a 4-dB or 7-dB power penalty 相似文献
10.
A 4-bit optical true-time-delay feeder incorporating an integrated electro-absorption modulation distributed feedback (DFB) laser for X-band phased array antennas is demonstrated. The integrated electro-absorption modulation DFB laser is an attractive device that provides a very compact, low-cost solution for optical true-time-delay systems. The variable delay line is constructed by cascaded magneto-optic switches, which have fast switching speed. The integrated electro-absorption modulation DFB laser system shows high signal-to-noise ratio up to 58dB, and the transmission performance of the system is relatively good and accredited. 相似文献
11.
T. Ido H. Sano S. Tanaka H. Inoue 《Photonics Technology Letters, IEEE》1995,7(12):1421-1423
Frequency-domain measurement of carrier escape times in reverse-biased multiple-quantum wells (MQW's) is proposed and demonstrated. Measurement and analysis of opto-to-electrical (OE) frequency response give the escape times of both electrons and holes with excellent time resolution. Using this technique, we measured escape times in an InGaAs-InAlAs MQW electro-absorption modulator and estimated the carrier density in the wells during optical input. This measurement can clarify the optical saturation effect in optical devices such as MQW electro-absorption modulators. 相似文献
12.
Feldster A. Shapira Y.P. Horowitz M. Rosenthal A. Zach S. Singer L. 《Lightwave Technology, Journal of》2009,27(8):1027-1033
We demonstrate experimentally an optical system for under-sampling several bandwidth-limited signals with carrier frequencies that are not known apriori and can be located anywhere within a very broad frequency region between 0-18 GHz. The system is based on under-sampling asynchronously at three different sampling rates. The optical pulses required for the under-sampling are generated by a combination of an electrical comb generator and an electro-absorption optical modulator. To reduce loss and improve performance the implementation of the optical system is based on a wavelength division multiplexing technique. An accurate reconstruction of both the phase and the amplitude was obtained when two chirped signals each with a bandwidth of about 150 MHz were sampled. 相似文献
13.
14.
Maguire P.J. Barry L.P. Krug T. Guo W.H. O'Dowd J. Lynch M. Bradley A.L. Donegan J.F. Folliot H. 《Lightwave Technology, Journal of》2006,24(7):2683-2692
Due to the introduction of new broadband services, individual line data rates are expected to exceed 100 Gb/s in the near future. To operate at these high speeds, new optical signal processing techniques will have to be developed. This paper will demonstrate that two-photon absorption in a specially designed semiconductor microcavity is an ideal candidate for optical signal processing applications such as autocorrelation, sampling, and demultiplexing in high-speed wavelength-division-multiplexed (WDM) and hybrid WDM/optical time-division-multiplexed networks. 相似文献
15.
We have demonstrated a 12Gsample/s continuous time ADC system using wavelength division sampling. Three 4Gsample/s optical pulse trains operating at different wavelengths are interleaved in time to achieved a rate of 12Gsample/s. The interleaving and demultiplexing of the samples is performed using only passive optical filters. Three 4Gsample/s electronic ADCs are then used to digitise the data, the complete signal being reconstructed in the digital domain 相似文献
16.
《Lightwave Technology, Journal of》2008,26(13):1835-1839
17.
Cullen T.J. Rourke H.N. Chew C.P. Baker S.R. Bricheno T. Byron K.C. Fielding A. 《Electronics letters》1994,30(25):2160-2162
A compact all-fibre design, composing two identical Bragg gratings written on to the arms of a fused fibre Mach-Zehnder interferometer, has been used to produce a low-loss wavelength drop and insert filter for wavelength division multiplexing/demultiplexing applications in optical fibre communication systems. A prototype device has been produced which can multiplex/demultiplex a signal centred on 1558.7 nm with any other wavelength in the 1550 nm transmission window with a maximum insertion loss of 1.0 dB 相似文献
18.
Schreieck R.P. Kwakernaak M.H. Jackel H. Melchior H. 《Quantum Electronics, IEEE Journal of》2002,38(8):1053-1061
We present experimental and theoretical results on ultrafast nonlinear dynamics in InGaAsP semiconductor optical amplifiers (SOAs). Carrier heating, spectral hole burning, and two-photon absorption are analyzed by heterodyne pump-probe experiments which deliver basic model parameters like gain-phase coupling parameters of the material. The impact on the device performance induced by these physical effects is verified by cross-gain/cross-phase experiments on InGaAsP-based SOAs and Mach-Zehnder interferometer switches. In the co-propagation arrangement, the switching window with maximum transmission is shown to be 1.5 ps which translates into demultiplexing capabilities beyond 600 Gb/s. Calculations based on a distributed rate equation model show that, for high-speed applications, the switching window can be limited by pulse saturation and by subpicosecond nonlinear effects. 相似文献
19.
偏分复用系统中直接解复用反馈信号建模及验证 总被引:1,自引:1,他引:0
在采用直接解复用的偏分复用(PDM)系统中,反馈信号是决定系统解复用性能的关键因素,因此反馈信号的选取与正确建模至关重要。本文详细分析了两偏振态信号光相干性对基于光功率差和射频(RF)功率两种直接解复用反馈信号的影响,完善了相关的理论模型,建立了100Gbit/s的PDM-DQPSK传输系统仿真平台,对两种反馈信号的解复用效果进行了验证。结果表明,无论两偏振态信号光的相干性如何,基于光功率差的反馈信号都适用,而RF功率反馈信号只适用于信号光相干度较大的情况;在两种反馈信号均可以使用的情况下,它们的解复用效果基本相同,引入的光功率代价均约为0.1dB。 相似文献