共查询到20条相似文献,搜索用时 15 毫秒
1.
Yamada H. Sanjoh H. Kohtoku M. Takada K. Okamoto K. 《Lightwave Technology, Journal of》2000,18(9):1309-1320
We measured the phase and amplitude error distributions in InP-based arrayed-waveguide grating (AWG) multi/demultiplexers using Fourier transform spectroscopy with interferogram restoration. The interferogram restoration was used to reduce the effect of the group-velocity dispersion of the waveguide. It was based on a wavenumber scale transformation or a dispersion balance between two arms in the interferometer. We derived a criterion for choosing the appropriate restoration method by estimating the worst-case measurement error in the presence of second order dispersion. After selecting a method using the derived criterion, we obtained isolated fringe patterns, from which we were able to obtain the phase and amplitude distributions in 50 and 200 GHz AWGs. Using the obtained distributions, we examined the origin of the crosstalk and chromatic dispersion in InP-based AWGs. The results revealed that the main origin is phase error as found with SiO2 -based AWGs 相似文献
2.
3.
4.
Estimation of waveguide phase error in silica-based waveguides 总被引:5,自引:0,他引:5
A new estimation method is proposed in order to clarify waveguide phase error factors. Using the proposed method, it is possible to analyze such factors as core size error and refractive index error, which cause optical phase error in waveguides. This method is applied to silica-based waveguides to estimate the waveguide phase error. This revealed an average core size error of 2.1×10-3 μm and an average refractive index error of 1.9×10-6. Finally, based on the measured phase error values, the optimum arrayed-waveguide grating (AWG) configuration is considered with a view to achieving low crosstalk 相似文献
5.
It has been difficult to measure the phase error distribution of a large-channel-spacing arrayed-waveguide grating (AWG) with optical low coherence interferometry (OLCI). In this reported work OLCI was successfully used to measure the slowly varying component in the distribution of a 1 THz-spaced AWG that was the primary filter in an ultra-high-density multi/demultiplexer. The spectral sidelobe of the AWG can be reduced by using the component to achieve the lowest possible accumulated crosstalk in the multi/demultiplexer. 相似文献
6.
An AWG-based 10 Gbit/s colorless WDM-PON system using a chirp-managed directly modulated laser
下载免费PDF全文
![点击此处可从《光电子快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We propose an arrayed waveguide grating(AWG)-based 10 Gbit/s per channel full duplex wavelength division multiplexing passive optical network(WDM-PON).A chirp managed directly modulated laser with return-to-zero(RZ) differential phase shift keying(DPSK) modulation technique is utilized for downlink(DL) direction,and then the downlink signal is re-modulated for the uplink(UL) direction using intensity modulation technique with the data rate of 10 Gbit/s per channel.A successful WDM-PON transmission operation with the data rate of 10 Gbit/s per channel over a distance of 25 km without any optical amplification or dispersion compensation is demonstrated with low power penalty. 相似文献
7.
Weiguo Yang 《Quantum Electronics, IEEE Journal of》2007,43(7):568-571
Random phase error due to fabrication process causes the filter response of arrayed-waveguide grating (AWG) to degrade, especially in terms of crosstalk. In the side-lobe region, which is critical to the channel crosstalk performance, each instantiation of the random phase error can yield a significantly different filter transmission than that of the average for that level of phase error. In this report, the statistical behavior of the AWG filter transmission in the side-lobe region is studied analytically. Both the distribution of random side-lobe level at a given wavelength and an upper bound of the outage probability for side-lobe maxima are given in a simple closed form. Accordingly, a crosstalk margin needs to be allocated to ensure a given fabrication yield and this is shown to depend on the fractional bandwidth of the AWG filter. For filter shapes that are close to Gaussian, this crosstalk margin can be 8 dB or more above the average crosstalk level, for small fractional bandwidth of about 1% and fabrication yields of 80% or higher. These relations should be useful to AWG designers particularly when the underlying fabrication process is susceptible to nonnegligible random phase errors. 相似文献
8.
为了在雷达回波数据压缩中较好地保留目标的相位信息,研究了基于非线性离散余弦变换(DCT)和自适应小波贪婪(AWG)算法的幅相压缩性能。运用上述2种算法对宽带回波信号分别进行了正交I/Q压缩和幅相压缩实验。通过性能指标CSNR(压缩信噪比)和CPSD(压缩相位标准差),比较了I/Q压缩和幅相压缩的压缩性能。结果表明,同传统的I/Q压缩相比,幅相压缩能很好地保留目标的幅相信息;上述2种幅相压缩方法在不同信噪比情况下各有优势,非线性DCT幅相压缩适宜于压缩低信噪比宽带回波信号,基于AWG算法的幅相压缩则适宜于压缩高信噪比回波信号。 相似文献
9.
为了适应高速率大色散光纤信道对链路色散的精确补偿要求,研究并提出了一种基于射频信号2阶零功率点的信道色散测量方案。采用信号两边带的位相差来测量光纤链路中的色散值,通过在发射端加载射频信号,可以得到接收端射频信号功率大小随链路色散值的周期性变化关系,从仿真光纤链路色散随射频信号频率的变化曲线获得接收端射频信号2阶零功率点位置。结果表明,基于射频信号2阶零功率的信号测量方案色散测量误差可控制在±10ps/nm范围内。相较于1阶零功率点,基于射频信号2阶零功率点信道色散测量方案可满足高速率、长距离大色散光纤信道对色散值的精确测量需求。 相似文献
10.
Kohtoku M. Hirono T. Oku S. Kadota Y. Shibata Y. Yoshikuni Y. 《Lightwave Technology, Journal of》2004,22(2):499-508
In a lightwave circuit using a strongly confined waveguide, higher order leaky modes must be suppressed to obtain ideal characteristics, especially in arrayed waveguide gratings (AWGs). Propagation loss for higher order leaky modes in InP-based deep-ridge waveguides was investigated by simulation and experiment. A highly sensitive loss measurement method based on optical low-coherence reflectometry was used to determine the loss, and the relationship between the loss for the higher order mode and AWG crosstalk was investigated. Optimizing the deep-ridge waveguide parameters, especially the core thickness, the refractive index of the core, and the etch depth under the core, significantly reduced the propagation loss for the higher order leaky mode. The effective elimination of the higher order modes will enable fabrication of low-crosstalk AWG routers. 相似文献
11.
Lee C.D. Wei Chen Qiang Wang Yung-Jui Chen Beard W.T. Stone D. Smith R.F. Mincher R. Stewart I.R. 《Lightwave Technology, Journal of》2001,19(11):1726-1733
The crosstalk performance of an arrayed-waveguide grating (AWG) multiplexer or demultiplexer is primarily caused by random optical phase errors introduced in the arrayed waveguides. Because the layout of waveguides on a wafer is patterned via photomask through the photolithography process, the resolution of a photomask has a direct influence on the phase errors of an AWG. The paper presents a theoretical analysis on the phase error caused by photomask resolution and other basic design parameters. Both calculation and measurement results show that a high-resolution photomask (better than 25 nm) is a critical requirement to produce low-crosstalk (less than -30 dB) AWG demultiplexers. We also investigate the effect of nonideal power distribution in the arrayed waveguides because it contributes considerable phase errors when material impurity is not well controlled during wafer fabrication. Basic criteria of power profile truncation, number of grating waveguides, and material index variation are also summarized 相似文献
12.
13.
The noise power spectral density in interferometric systems was studied theoretically and experimentally. The influence of 1/f frequency modulation noise, white noise, and source dispersion are shown in the conversion of phase noise into intensity noise. The direct relative intensity noise (RIN) is compared with the RIN caused by phase-to-intensity noise conversion, and the root mean square of equivalent interferometer phase error was studied. The influence of the interferometer operating point is shown on the noise power spectrum. The results can be employed to estimate the influence of the these effects in phase-to-intensity noise conversion in radio-frequency-modulated optical links, which use either self-delayed interferences or interferometers. These results can be applied to optical signal processing, radar signal processing, etc., which often use interferometers. 相似文献
14.
《Photonics Technology Letters, IEEE》2009,21(22):1701-1703
15.
通过分析传统任意波形发生器(AWG)的局限性,提出了一种基于通用串行总线(USB)和直接数字频率合成(DDS)技术的新型虚拟AWG的设计方法,并详细讨论了虚拟AWG的软件设计及硬件实现。该波形发生器操作灵活,可以产生任意波形的周期性信号,能灵活控制波形的幅值、频率和相位,并且在很宽的频率范围内快速切换频率,在自动测试、雷达等方面有着广泛的应用价值。 相似文献
16.
17.
M.T. Hill T. de Vries H.J.S. Dorren X.J.M. Leijtens J.H.C. van Zantvoort J.H. den Besten E. Smalbrugge Y.S. Oei J.J.M. Binsma G.D. Khoe M.K. Smit 《Photonics Technology Letters, IEEE》2005,17(5):956-958
An integrated InP-InGaAsP two-state coupled-laser device for use in optical packet switching and signal processing is presented. The two states are identified by distinct lasing wavelengths. Single-mode lasing occurs in both states and the contrast ratio between the two states is 35 dB. Switching between states with optical pulses is demonstrated. The use of an arrayed waveguide grating (AWG) and ring laser configuration permits monolithic integration without the need for cleaved facets. How the AWG can be used to obtain partial isolation between multiple interconnected devices is also discussed. 相似文献
18.
Calabretta N. Presi M. Proietti R. Contestabile G. Ciaramella E. 《Photonics Technology Letters, IEEE》2007,19(16):1227-1229
We present an innovative architecture to realize a single feeder bidirectional amplified wavelength-division-multiplexing/time-division-multiplexing passive optical network based on modified nonreturn-to-zero differential phase-shift keying (DPSK) downstream signals at 20 Gb/s and a narrowband arrayed waveguide grating (AWG). The AWG plays at the same time the role of channel distributor, simultaneous demodulator for all DPSK channels, and eliminates the need for chromatic dispersion compensation. A saturated semiconductor optical amplifier (SOA) provides bidirectional amplification to compensate the splitter losses. The remodulated upstream signals are obtained at 1 Gb/s by means of a reflective SOA. Experimental results show error-free operation on both downstream and upstream signal. 相似文献
19.
20.
This letter reports a spectral phase encoder using an arrayed-waveguide grating (AWG) with phase-adjustable structure. It consists of the 12.5-GHz spacing eight-channel AWG phase-adjustable structure with deep trenches formed in the waveguides. The spectral phase encoding of optical short pulses at the repetition rate of 12.5 GHz using the AWG encoder was successfully demonstrated. 相似文献