单片集成光波导波分器的研究

简述了单片集成光波导波分器的原理和制备工艺。并用同一根光纤传输的两波长激光束（６３２．８ｕｍ，７８５．５ｕｍ）测试了该器件的波分特性。实验中成功地观察到同光纤传输的两个不同波长的激光信号在波分器的输出端分离。     

Phased-array wavelength demultiplexer with flattened wavelengthresponse

A four-channel phased-array wavelength demultiplexer with a flattened wavelength response has been realised for the first time in InP/InGaAsP at 1.54 μm by employing multimode output waveguides. The device has 2 nm channel spacing and a flat response (within 1 dB) of 17 nm     

一种基于三芯光纤的模式复用器/解复用器的设计

提出了一种基于三芯光纤的模式复用器/解复用器,三个纤芯包括两个相同的单模纤芯和一个少模纤芯,在少模纤芯中写入长周期光纤光栅以实现单模纤芯中LP01模与少模纤芯中LP11模间的转换。同时从两个单模纤芯输入LP01模,能激发少模纤芯中两个简并的LP11,a模和LP11,b模。采用光束传播法分析了该模式复用器/解复用器的耦合特性及串扰。数值模拟结果显示,若以少模纤芯中LP11模输出能量大于-1dB的波长范围作为该模式复用器/解复用器的工作带宽,则能够达到23nm,并且少模纤芯中生成的其他模式的输出能量皆比LP11模的输出能量小-21dB以上。该模式复用器/解复用器能够实现对少模光纤的模式复用与解复用,并具有极低的串扰。     

Practical realization of a high density diode-coupled wavelengthdemultiplexer

The design, development, and optical performance of a novel demultiplexer in which a photodiode array replaces the array of fibers at the output is described. The prototype diode-coupler high-density wavelength demultiplexer has 16 channels with 4-nm channel spacing. Its optical performance, with respect to insertion loss, optical passband, total optical crosstalk, and polarization response and taking into account expected component and manufacturing tolerances is good. In particular, an optical passband between ±0.7 nm and ±0.9 nm can be tolerated without deterioration in performance, reducing the need for precise laser wavelength control. In addition, the diode leakage currents achieved, although relatively large, do not constitute a significant penalty in receiver sensitivity for applications at 560 Mb/s or higher, and the diode capacitance is very low. It is concluded that this is an attractive solution for high-density wavelength-division multiplexing     

Wavelength demultiplexing using bends in a single-mode opticalfiber

A method of wavelength demultiplexing is developed that makes use of the wavelength and bend-radius dependence of the pure bend loss at single radius bends in a single-mode fiber. The light leaving the fiber at a bend forms one output of the demultiplexer. Equations are derived that predict the bend radii for the most-efficient operation of the demultiplexer and the power extracted from the fiber at each wavelength. The demultiplexer operates over the wavelength range corresponding to V numbers from 2.4 to 1.6. A two-wavelength demultiplexer formed from 90° bends is constructed and tested. Collection efficiencies of 70% and insertion losses of less than 2 dB are shown to be possible. Crosstalk isolation in excess of 40 dB can be achieved with the aid of optical wavelength filters. The performance of a three-wavelength demultiplexer is also considered     

10Gb/s0.25m CMOS1∶4键合分接器

首先分析了1∶4分接器的树型结构及其主要特点。在此基础上,进一步探讨了树型结构中所用的1∶2分接器,并给出其中的锁存器电路结构。此外,还讨论了分频器电路及输入输出电路。最后分析了超高速键合电路并给出测试方案。测试结果表明,在采用标准0.25μmCMOS工艺设计的分接器中,本设计首次达到键合后能够在STM-16和STM-64所要求的数据速率上稳定工作的性能,最高工作速率达10.58Gb/s。     

基于慢光效应的解波分复用器的设计与研究

为了设计一种基于正方晶格光子晶体波导的三端口解波分复用器,利用光子晶体的光子带隙特性和光在光子晶体慢光波导中的传输特性,并采用平面波展开法及时域有限差分法对解波分复用器的特性进行了理论分析,数值计算了解复用器的空间和光谱分布特性。结果表明,调整波导中与波导紧邻的第1排柱子的位置,使三部分波导中传输的慢光频率发生改变,通过合理的结构设计,利用慢光模式传输的特点将不同频率的光从不同的输出端输出,可实现解复用的目的。     

InGaAsP Y-branch grating demultiplexer

We report on the fabrication of a passive Y-branch wavelength-division demultiplexer with InGaAsP/InP rib waveguides. The wavelength-selective elements are Bragg reflection gratings on top of the two output ribs of the branch. A channel spacing of 13.5 nm in the 1.5?m region and a crosstalk attenuation of more than 18 dB for TE-polarised light were achieved.     

1092 Channel 2-D Array Demultiplexer for Ultralarge Data Bandwidth

We demonstrate 1 x 1092 channel wavelength demultiplexing with 50-GHz channel pitch and a 600-nm total bandwidth. Outputs from 1 x 40 channel arrayed waveguide gratings operating with multiple orders enter a free-space optical grating demultiplexer which separates the orders into a 2-D spot array, where the light can be coupled into discrete output fibers or operated on by a surface normal device (i.e., microelectromechanical system switch or detector array). Supercontinuum source input from 1140 to 1750 nm produced a 28 times 39 spot array at the output plane. The insertion loss for light is coupled into a single mode fiber ranged from 7 to 18 dB with less than 10-dB loss in channels between 1300 and 1750 nm. Bit-error-rate measurements show a negligible 0.1-dB power penalty at 10 GB/s.     

硅基竖直耦合三环谐振波分复用器的特性

对1×N信道硅基竖直耦合三环谐振波分复用器的传输特性进行了分析,给出了光学传递函数的公式.在中心波长1550.918nm、波长间隔1.6nm的情况下,对其振幅耦合比率、波谱响应、分光光谱、插入损耗、信道间的串扰进行了数值模拟.计算结果表明,该器件具有以下良好性能:若取小环与信道间的振幅耦合比率为0.27,小环与大环间的振幅耦合比率为0.06,该器件具有箱形波谱响应,输出光谱中的次峰值已被抑制到-25dB,谐振峰平坦且陡峭,3dB带宽约为0.28nm,每条输出信道的插入损耗及串扰较小,插入损耗小于0.71dB,串扰可降至-53dB以下.     

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     

Study of a SiGe-HBT-based 1：2 demultiplexer IC up to 100 Gb/s rate

An ultra-high speed 1:2 demultiplexer for optical fiber communication systems is designed utilizing the IHP 0.25 μm SiGe BiCMOS technology. The latch of the demultiplexer core circuit is researched. Based on the current measurement condition, a high-gain and wide-bandwidth clock buffer is designed to drive large load. Transmission line theory for ultra-high speed circuits is used to design matching network to solve the matching problem among the input, output and internal signals. The transient analysis sho...     

基于三芯光纤的波分解复用器的研究

本文设计了基于常规线型排列三芯光纤的新型波分解复用器,比起基于多芯的光子晶体光纤的波分解复用器,该波分解复用器有着容易制作,且易于与常规光纤对接的优点。由耦合理论可知,对于两个失配的平行光波导,两波导的模式耦合是不完全的。通过设计使两个非对称平行光波导在某波长上传播常数匹配,此时两个波导就可完全耦合,从而实现滤波。通过选择合适的光纤长度,使得在光纤的输出端,不同波长的光从不同的波导端口输出,实现波分解复用的功能。本文利用全矢量光束传播法仿真发现,在1cm处可以实现波长1.31um和1.55um光的解复用。     

Demonstration of novel optical multichannel grating demultiplexer receiver (MGD) for HDWDM systems

A novel implementation of a multichannel grating demultiplexer receiver suitable for HDWDM applications is described. The prototype receiver, capable of 10-channel operation spaced at 4 nm, uses a 16-element GaInAs/InP monolithic linear photodetector array and silicon preamplifier ICs. The sensitivity at the input to the demultiplexer is -31 dBm at 200 Mbit/s. Optical and electrical crosstalk measurements in the receiver are presented, and limited tests have shown that there is a negligible crosstalk penalty.<>     

A Spatial-Distance-Controllable Demultiplexer Using a Chirped Volume Holographic Grating

In this letter, we introduce a demultiplexer with a function of controlling spatial distance based on a chirped volume holographic grating. The chirped grating is recorded by illuminating a photopolymer film under the interference of convergent and divergent beams. The theoretical and experimental results show that the position of the focused points of the diffracted beam at the readout stage depends on the distance between the grating and the output lens. This characteristic can be utilized to control the channel spacing and spatial distance in the dense wavelength-division-multiplexing demultiplexer.     

Gating demultiplexer integrated with MSM detector array inInGaAs/AlGaAs/GaAs for WDM

The authors demonstrate the integration of a grating demultiplexer with curved output waveguides and a MSM photodetector array in InGaAs/AlGaAs/GaAs operating in the 1-μm wavelength region. The structure provides 38 channels with 1-nm channel spacing. The total loss, including scattering from the unmetallized grating, is about 17 dB. A channel crosstalk of -11 dB is obtained. The FWHM of the channel pass band is 0.5 nm     

Monolithic integrated wavelength demultiplexer based on a waveguideRowland circle grating in InGaAsP/lnP

We present detailed modeling and experimental results for an improved design of an InGaAsP-InP wavelength demultiplexer based on a monolithically integrated Rowland circle grating. The design incorporated ten wavelength channels at 1.55 μm with a uniform spacing of 2 nm. The total on-chip loss was about 10 dB and the crosstalk between adjacent channels was as low as -25 dB. It was shown that low-loss etched turning mirrors can reduce the total on-chip loss by about 4 dB compared to traditional 90° curved multimode waveguides. By replacing standard flat grating facets with retro-reflecting V-shaped facets in the echelle grating, the loss was further reduced by 4 dB. Polarization independent operation within a passband of 0.5 nm was achieved by using multimode output waveguides. The potential sources producing the crosstalk have been analyzed and fabrication modifications for further improvement are suggested     

8通道-1.6nm Si纳米线阵列波导光栅的设计与制作

设计了基于绝缘层上硅(SOI)材料的8通道Si纳米线阵列波导光栅(AWG),器件的通道间隔为1.6nm,面积为420μm×130μm。利用传输函数法模拟了器件传输谱,结果表明,器件的通道间隔为1.6nm,通道间串扰为17dB。给出了结合电子束光刻(EBL)和感应耦合等离子(ICP)刻蚀技术制备器件的详细流程。光谱测试结果分析表明,器件通道间隔为1.3～1.6nm,通道串扰为3dB,中心通道损耗为11.6dB。     

刻蚀衍射光栅像差特性分析

对作为波分复用关键器件之一的刻蚀衍射光栅(EDG)的像差特性提出了一种简单方便的计算方法,分析了像差对刻蚀衍射光栅频谱响应的影响.理论推导了基于基尔霍夫衍射、角谱衍射以及快速傅里叶变换等方法.最终证明彗差会造成谱形失称,明显降低耦合效率;而球差则会明显地增加串扰.并指出当像差存在时通过输出端加ta per结构,并不能显著改善器件的串扰特性.     

320-to-40-gb/s demultiplexing using a single SOA assisted by an optical filter

We demonstrate excellent all-optical demultiplexing of 40-Gb/s base-rate channels out of 160- and 320-Gb/s single polarization optical time-division-multiplexed data streams. The demultiplexer utilizes a semiconductor optical amplifier and an optical filter placed at the amplifier output. The center wavelength of the filter is blue-shifted from the wavelength of the clock signal, so that ultrafast chirp dynamics can be employed for optical switching. Error-free demultiplexing was achieved at very low optical switch powers: 3.5 mW (160-Gb/s data), 6.3 mW (320-Gb/s data), and 0.09 mW (40-GHz clock). The proposed demultiplexer has a simple structure and allows monolithic integration.