Analysis of Optical Singal Transmission Characteristics in AWG Multi/Demultiplexer with Electromagnetic Field Theory

Based on the electromagnetic field theory,the optical signal transmission characteristics in input/output waveguides,slab waveguides and arrayed waveguides of the arrayed waveguide grating(AWG) multi/demultiplexer are analyzed.The relationship between the physical parameters such as geometry sizes and relative refractive index in AWG multi/demultiplexer and the optical signal transmission characteristics are discussed.This theoretical study can be used for optimizing the design and improving the performance of the AWG multi/demultiplexer.     

Polymeric optical waveguide circuits formed using silicone resin

Polymeric optical waveguides fabricated using a newly developed silicone resin have a low birefringence as well as low propagation loss and good environmental stability. Optical waveguide circuits including a directional coupler, an arrayed waveguide grating (AWG) multi/demultiplexer, and a digital thermooptic (TO) switch are successfully realized using the silicone resin     

1.5%-/spl Delta/ athermal arrayed-waveguide grating multi/demultiplexer with very low loss groove design

We describe a compact 1.5%-/spl Delta/ athermal silica-based 100-GHz-spacing 16-channel arrayed-waveguide grating (AWG) multi/demultiplexer with a modified groove design for a very low excess loss. We propose new approaches for modifying the shape of the grooves and the arrayed waveguides and optimize the shape modifications for 1.5%-/spl Delta/ waveguides. By employing this modified groove design, we greatly reduced the groove excess loss from 1.9 to 0.4 dB in the 1.5%-/spl Delta/ athermal AWG.     

阵列波导光栅复用器优化设计的数值计算

阵列波导光栅(AWG)复用／解复用器的优化设计计算是集成光波导器件设计计算中的难点．文章应用AWG光信号传输特性和光栅方程，提出了AWG组成部分输入／输出波导、阵列波导、平板波导相关参数及阵列波导结构优化设计的数值计算方法，给出了具体的计算数值；该计算方法解决了AWG复用器优化设计计算的问题，为进一步建立AWG的计算机辅助设计提供了基础．     

Improve Channel Uniformity of an Si-Nanowire AWG Demultiplexer by Using Dual-Tapered Auxiliary Waveguides

Dual-tapered auxiliary waveguides at the exit of the waveguide array are introduced to improve the channel uniformity of an Si-nanowire-based arrayed waveguide grating (AWG) demultiplexer. By using a hybrid simulation method, the dual-tapered auxiliary waveguides of the AWG demultiplexer are optimized reliably and efficiently. A 12-channel AWG demultiplexer is designed as an example, and a small nonuniformity (< 0.5 dB) is achieved.     

The role of photomask resolution on the performance ofarrayed-waveguide grating devices

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     

由5个AWG组成的600个通道的光波分复用器

本文介绍了有 6 0 0个通道、通道间隔为 2 5 GHz的光波分复用器。该波分复用器是由 1个 8通道间隔为 1.875 THz的母阵列波导光栅 (AWG)和 4个 12 8× 12 8的通道间隔为 2 5 GHz的子阵列波导光栅级联而成的。这种设计因为其体积小而在超密集的波分复用器的发展中更富有竞争力     

Crosstalk reduction in N×N WDM multi/demultiplexers bycascading small arrayed waveguide gratings (AWG's)

This paper shows a new scheme which improves the crosstalk performance of large optical multi/demultiplexers, a key component in wavelength division multiplexing (WDM) systems. This scheme uses arrayed waveguide gratings (AWG's) of various sizes and requires no additional equipment. It is well known that a large multi/demultiplexer can be constructed by cascading small multi/demultiplexers. We have studied the impact of the number and size of AWG stages on crosstalk performance. This paper proves that to obtain a multistage multi/demultiplexer with minimum crosstalk, the total channel number of each AWG stage must be minimized. For example, cascading 10-channel AWG's and 11-channel AWG's improves the crosstalk performance of a 110-channel multi/demultiplexer by about 7.5 dB. Furthermore, the crosstalk performance degradation due to fabrication error is theoretically investigated taking channel bandwidth into account. Optimum design parameters of multistage AWG's are introduced: When the AWG suppression ratio is 30 dB and the ratio of channel bandwidth to channel spacing is about 0.24, the degradation in crosstalk performance due to fabrication error is minimized. The tradeoff between the crosstalk performance and the efficiency in terms of hardware and wavelength are also discussed. It is discovered that this simple scheme can yield a crosstalk-free WDM router. Crosstalk reduction obtained by this scheme allows the realization of flexible multiwavelength networks based on wavelength routing     

阵列波导光栅复用器的数学特性

叙述了基于阵列波导光栅复用器的结构与原理,在此基础上分析了其输入与输出信号的傅里叶变换、信号传输、信号循环移位,复用、解复用和波长路由的信号矩阵变换等光信号时空变换和光信号处理的数学特性,拓宽了阵列波导光栅波分复用器的应用领域。     

非对称结构阵列波导光栅解复用器的传输效率

基于光波导模场分布的高斯函数近似表达式,给出非对称结构阵列波导光栅解复用器信号通道对其中心波长光谱响应度的函数表达式,分析了光谱响应度与器件基本参数的关系.基于实际通道信号光谱分布的高斯函数近似表达,给出非对称结构阵列波导光栅解复用器信号通道对实际输入信号的传输效率,分析了输入信号光谱宽度对器件通道实际传输效率的影响.     

Low-crosstalk 10-GHz-spaced 512-channel arrayed-waveguide gratingmulti/demultiplexer fabricated on a 4-in wafer

We report a 10-GHz-spaced 512-channel arrayed-waveguide grating (AWG) multi/demultiplexer fabricated on a 4-in wafer. We achieved this by folding the 7-cm-long slab waveguides of a conventionally configured AWG, so that the whole configuration was contained in the wafer and then attached reflecting mirrors at the folded parts. Phase compensation of the fabricated AWG was performed by means of ultraviolet irradiation through a metal mask     

Measurement of slowly varying component in phase error distribution of a large-channel-spacing arrayed-waveguide grating

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.     

5 GHz-spaced, eight-channel, guided-wave tunable multi/demultiplexer for optical FDM transmission systems

A 5GHz-spaced, eight-channel, guided-wave tunable multi/demultiplexer for optical frequency-division-multiplexing (FDM) transmission systems is demonstrated. It is constructed with high-silica channel waveguides and thin-film heaters loaded on the waveguides for frequency tuning     

Guided-wave optical wavelength-division multi/demultiplexer using high-silica channel waveguides

A guided-wave optical waveguide-division multi/demultiplexer for bidirectional transmission at (0.81 ?m, 1.2 ?m)/(0.89 ?m, 1.3 ?m) wavelengths has been realised using high-silica channel waveguides on silicon substrate. The multi/demultiplexer connected with graded-index multi-mode fibres shows a loss of 3.5?5 dB together with far-end and near-end crosstalk levels less than ?30 dB and ?50 dB, respectively.     

Transport performance in optical path cross-connect systememploying unequally spaced channel allocation

The transmission performance of an optical path cross-connect (OPXC) system employing unequally spaced channel allocation is evaluated. Four-wave mixing (FWM) light is generated at a different wavelength from all other signal lights when unequally spaced channel allocation is employed in the OPXC system. This evaluation shows that FWM light degrades the transmission performance because the received FWM light power is added to the signal and closes the eye aperture of the signal. The FWM light is rejected by the employed demultiplexer when the full-width at the half maximum (FWHM) of the demultiplexer is reduced. The FWHM of the demultiplexer should be designed in order to minimize the transmission performance degradation caused by the FWM crosstalk. The FWHM of the arrayed-waveguide-grating (AWG) demultiplexer that is developed for the OPXC system is 0.6 nm, and a 400 km transmission with optical path cross-connections is successfully completed in a 4×4 OPXC system test-bed employing unequal channel spacing with a 10 GHz frequency slot, i.e., the minimum frequency separation between signal light and FWM light. Further reduction in the FWM crosstalk is required for the OPXC system in order to support longer distances between nodes. The distance of 120 km ×5 requires that the frequency slot is increased to 30 GHz and the FWHM of the AWG demultiplexer is 0.3 nm     

Si纳米线阵列波导光栅制备

采用绝缘层上Si(SOI)材料设计制备了3×5纳米线阵列波导光栅(AWG),器件大小为110μm×100μm。利用简单传输法模拟了器件的传输谱,并采用二维时域有限差分(FDTD)模拟中心通道输出光场的稳态分布,模拟结果表明,器件的通道间隔为11 nm,通道间的串扰为18 dB。通过电子束曝光(EBL)和感应耦合等离子(ICP)刻蚀制备了所设计的器件,光输出谱测试分析表明,器件中心通道的片上损耗为9 dB,通道间隔为8.36～10.40 nm,中心输出通道的串扰为6 dB。在误差允许范围内,设计和测试的结果一致。     

Measurement of phase and amplitude error distributions in InP-basedarrayed-waveguide grating multi/demultiplexers

The authors have measured the phase and amplitude error distributions in an InP-based arrayed-waveguide grating (AWG) multi/demultiplexer using Fourier transform spectroscopy and signal data processing. The signal data processing technique was based on wavenumber scale transformation and was applied to reduce the effect of second-order dispersion in a measured interferogram. The results reveal that the main origins of the crosstalk and dispersion in an InP-based AWG are random and slowly-varying phase errors, respectively     

基于AWG实现OADM：模型与方法研究

波分复用光网络系统的关键器件是波分复用和解复用器,本文提出一种简化的位相波导光栅（AWG）原理模型,分析了AWG基本原理与相关特性,比较分析了基于AWG实现光分插复用（OADM）的三种方案四种方法的串扰特性,首次提出减少串扰的第四种实现OADM方法并经过实验验证。     

氟化聚合物光谱响应平坦化阵列波导光栅的优化设计和制备

本文基于阵列波导光栅(AWG)的传输理论,利用含氟聚合物(PFS-co-GMA)共聚物材料,对17×17信道光谱响应平坦化AWG波分复用器进行了参数优化.由于在聚合物阵列波导光栅器件的制备过程中,选用了反应离子刻蚀(RIE)工艺和蒸汽回溶技术,形成的梯形截面波导芯,使AWG传输的光产生相位移,导致传输光谱移动,引起串扰...     

1-GHz-spaced 16-channel arrayed-waveguide grating for a wavelength reference standard in DWDM network systems

We fabricated a 1-GHz-spaced 16-channel arrayed-waveguide grating (AWG) by using a new AWG configuration where the path of each arrayed waveguide winds backward and forward across a 4-in diameter wafer without crossing any other waveguides. The ultra-narrow (< 1 GHz) and stable transmission bands of this AWG can be used to construct a wavelength reference standard covering the S, C, and L bands in the dense wavelength-division-multiplexing network systems whose frequency deviation is /spl plusmn/160 MHz.