排序方式: 共有54条查询结果,搜索用时 812 毫秒
21.
<正>A cost-effective method of multi-receiver optical orthogonal frequency-division multiplexing(OOFDM) system is proposed to reduce the requirement for the speed of the receiver and the size of fast Fourier transform(FFT).The sampling rate of analog-to-digital converters(ADCs) can be reduced to 1/N of the original signal bandwidth in an N-receiver system.Aided by signal predistortion at the transmitter, aliasing-free signal can be retrieved independently and directly at the low speed receivers.A back-to-back experimental result is given for a two-receiver system.The effect of the electrical filters added before the ADC is studied and the analysis for filters optimization is given. 相似文献
22.
All-Optical AND Logic Gate without Additional Input Beam by Utilizing Cross Polarization Modulation Effect
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A novel design of all-optical AND gate is proposed by using cross polarization modulation effect in a semiconductor optical amplifier. In this scheme, an additional continuous-wave beam is not required as that in traditional scheme. AND output is obtained on either of two input signal wavelengths. The AND scheme is numerically simulated and experimentally demonstrated at a bit rate of 10 Gb/s successfully. 相似文献
23.
A method of multi-channel receiving for high bit rate heterodyne direct-detection optical orthogonal frequency-division-multiplexing (OOFDM) system is proposed to reduce the sampling rate demand of analog-to-digital converter (ADC). The sampling rate of ADCs can be reduced to 1/N that of the original signal bandwidth in an N-channel receiving system. Aided by a succeeding digital signal processing (DSP) at the receiver, aliasing free signal can be recovered. A back-to-back experimental result is given for a 4-channel system, based on which, a down conversion process for heterodyne can be reduced. The signal rebuilding algorithm is given and analyzed in its complexity and noise tolerance. 相似文献
24.
本文给出了半导体激光器光学可双稳静态特性的分析。使用电子和光子密度的非线性速率方程,得到了光学可双稳半导体激光二极管(BILD)光输出的一种简单模型。该模型强调物理机制以及和双稳性有关的参数给出了态方程,并解释了BILD的主要特征。在P_oP_i特性中具有很大滞后回线的双稳性是BILD的突出特点。 相似文献
25.
A Step—by—Step Tunable Compound External Cavity Semiconductor Laser with Two—Side Feedback Coupling
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A kind of compound external cavity semiconductor lasers(CECSL) is presented,by which laser with a discretely tunable wavelength can be obtained to meet the potential demands of the wavelength division multiplexing system.By the introduction of two-side feedback coupling in the CECSL,the CeCSL can operate more efficiently,and its side-mode suppression ratio is high up to 50dB. 相似文献
26.
B-ISDN的交换技术必须是宽带交换技术,光ATM交换是在光交换和电ATM交换基础上形成的一种新的交换技术,它以简洁的系统结构,相对低的系统及用户终端成本、灵活的网络功能,实现数+Gbit/s甚至数百Gbit/s的各种信号码率的全透明交换 相似文献
27.
Amplitude Regenerative Characteristics of RZ-DPSK Wavelength Converter Based on Four-Wave Mixing in SOA
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We investigate the phase-preserving amplitude regenerative characteristics of the return-to-zero (RZ) differential- phase-shift-keying (DPSK) wavelength conversion based on four-wave m/xing (FWM) in a semiconductor optical amplifier (SOA). The Q-factor and the optical signal-to-noise ratio (OSNR) before and after conversion are experimentally obtained and analysed in different input noise power levels. In both the continuous-wave and synchronous clock pumping cases, we find that there is amplitude clamping in the FWM conversion due to the gain saturation of SOA, which can suppress the amplitude fluctuation of the converted DPSK signal before and after demodulation. We have achieved 2-dB Q penalty improvement in our experiment demonstration of lOGbit/s RZ-DPSK signal with OSNR lower than 19dB. 相似文献
28.
Performance improvement of 10-Gb/s XGM wavelength conversion by using polarization control structure
By utilizing the cross polarization modulation effect in semiconductor optical amplifier (SOA), the extinction ratio of cross gain modulation (XGM) wavelength conversion was enhanced, the pattern effect was significantly reduced, and the power penalty of wavelength conversion was reduced by 5 dB simultaneously. Furthermore, by adjusting the settings of polarization controllers, both inverted and non-inverted wavelength conversion can be achieved right in the same wavelength converter. 相似文献
29.
30.