32-channel arrayed waveguide grating multiplexer using low loss fluorinated polymer operating around 1550 nm

A 32 × 32 arrayed waveguide grating (AWG) multiplexer operating around the 1550 nm wavelength has been designed and fabricated using highly fluorinated polyethers. The propagation loss of the slab waveguide is about 0.3 dB/cm at 1550 nm wavelength. The channel spacing of the AWG multiplexer is 0.8 nm (100 GHz). The insertion loss of the multiplexer is 10.3-15.3 dB and the crosstalk is less than −20 dB.     

System degradation due to phase error induced crosstalk in WDM optical networks employing arrayed waveguide grating multi/demultiplexer

The phase error induced crosstalk within arrayed waveguide gratings (AWG) have been investigated theoretically as well as simulation. For WDM system, a crosstalk level of −21.9 dB causes a power penalty of 1 dB for 64 channels and less than 0.5 dB for 16 channels and 32 channels, respectively. For crosstalk level of −30 dB and below, the power penalty is negligible. Crosstalk due to phase error also causes higher power penalty at higher bit rate. Bit rate of 10, 20 and 40 Gbits/s causes power penalty of 1 dB with crosstalk level of −41.5, −46.25 and −49 dB, respectively.     

Athermal silicon arrayed waveguide grating with polymer-filled slot structure

In this paper, an athermal silicon arrayed waveguide grating (AWG) with the assistance of a polymer-filled slot structure is proposed. Arrayed slot waveguides were used to replace arrayed silicon photonic wires (SPWs). By carefully controlling the temperature dependence of the effective index of the polymer-filled slot waveguides, the athermal silicon AWG is realized. Analysis shows that the center wavelength shift of the AWG can be down to 0.14 pm/°C.     

Athermal metal-free planar waveguide concave grating demultiplexer

An athermal metal-free planar waveguide concave grating demultiplexer is proposed. We designed the dielectric mirror at the grating facet instead of coating with the metal on the back wall of the grating facet. The transfer-matrix method is introduced to design the dielectric mirror and the reflectance spectral responses of the 2D waveguide structure are simulated using the FDTD software (RSoft, Inc.). To reduce the temperature sensitivity of the device, the three-focal-point method is introduced. We use the design example to show the high-reflectance bandwidth of the dielectric mirror. The fabrication errors are also taken into consideration. By using the numerical model of the scalar diffraction theory, the flat-top spectral responses of the channels are simulated.     

Analytical modeling of loss characteristics of a polymer arrayed waveguide grating multiplexer

Theoretical analysis is performed for the loss characteristics of a polymer arrayed waveguide grating (AWG) multiplexer around the central wavelength of 1.55 μm with the wavelength spacing of 1.6 nm. The total loss of the device includes the diffraction loss in the input and output (I/O) slab waveguides, bent loss caused by the AWG and I/O channels, leakage loss resulted from the high refractive index substrate, and propagation loss due to the absorption and scattering of the materials of the device. The effects of some structural parameters on the loss characteristics are investigated and discussed. The computed results show that when we select the core thickness as 4 μm, core width as 6 μm, pitch of adjacent waveguides as 15.5 μm, diffraction order as 50, the number of the arrayed waveguides as 91, that of the I/O channels as 17, confined layer thickness between the core and the substrate as 10 μm, distance between the focal point and the origin as 5500 μm, and central angle between the central waveguide and the x-axis (i.e. the vertical of the symmetrical line of the device) as 60°, the total loss of the device can be dropped to the range 3.79–7.93 dB.     

O波段8通道硅基二氧化硅平坦化阵列波导光栅的设计及制备

设计并制作了一款应用于IEEE 200/400GbE标准802.3bs的阵列波导光栅.该阵列波导光栅使用2.0%的超高折射率差硅基二氧化硅材料,使得芯片尺寸及损耗较小.为了获得平坦化的接收光谱,将输出波导进行展宽,采用多模波导结构,激发若干个高阶模,数个模式叠加使得原本高斯状的光谱顶部产生平坦化,形成箱形接收光谱.设计的阵列波导光栅的中心波长为1 291.10nm,通道间隔为800GHz,芯片尺寸为11mm×4mm.经过等离子增强化学气相沉积和感应耦合等离子刻蚀工艺制备了芯片,测试结果表明最小的插入损耗为-3.3dB,相邻通道间串扰小于-20dB,单通道1dB带宽在2.12~3.06nm范围,实现了良好的解复用和平坦化效果,在实际光通信系统中有一定的实用价值.     

Design and fabrication of arrayed waveguide grating using fluoropolymer PFS-co-GMA

A 33×33 polymer arrayed waveguide grating (AWG) multiplexer is optimized and fabricated. This device is made of polymeric materials named 2,3,4,5,6-pentafluorostyrene-co-glycidylmethacrylate (PFS-co-GMA). The central wavelength and wavelength spacing are designed to be 1550.918 and 0.8 nm, respectively. The calculated results are: the 3-dB bandwidth is about 0.24 nm, insertion loss is about 8.4 dB and crosstalk is −33.7 dB. The corresponding measured results are: the center wavelength is about 1550.85 nm, wavelength channel spacing is about 0.81 nm, 3-dB bandwidth is about 0.35 nm, crosstalk is about −20 dB, insertion loss is between 10.4 dB for the central port and 11.9 dB for the edge ports.     

Analysis for fabrication errors of arrayed waveguide grating multiplexers

Based on the transmission theory, parameter optimization is performed, and effects of fabrication errors on transmission characteristics are analyzed for a 33×33 polymer arrayed waveguide grating (AWG) multiplexer around the central wavelength of 1550.918 nm with the wavelength spacing of 0.8 nm. Simulated results show that fabrication errors result in the shift of the transmission spectrum, and lead to the increase of the crosstalk compared with the device theoretically designed. Furthermore, accumulation and compensation of fabrication errors are investigated. In order to realize the normal demultiplexing of the fabricated AWG device, the allowed fabrication errors are discussed.     

Compact SOI arrayed waveguide grating demultiplexer with broad spectral response

A compact eight-channel flat spectral response arrayed waveguide grating (AWG) multiplexer based on silicon-on-insulator (SOI) materials has been fabricated on the planar lightwave circuit (PLC). The 1-dB bandwidth of 48 GHz and 3-dB bandwidth of 69 GHz are obtained for the 100 GHz channel spacing. Not only non-adjacent crosstalk but also adjacent crosstalk are less than −25 dB. The on-chip propagation loss range is from 3.5 to 3.9 dB, and the total device size is 1.5 × 1.0 cm².     

650 nm聚合物阵列波导光栅波分复用器设计

选择在可见光波段具有较低吸收损耗的聚甲基丙烯酸甲酯-甲基丙烯酸环氧丙酯 共聚物作为波导包层材料,使用双酚A型环氧树脂作为折射率调节剂,根据材料的折射率设计了单模波导截面尺寸;然后,采用束传播法优化设计出16信道阵列波导光栅(AWG)器件的版图结构。利用Optiwave软件模拟了AWG器件的光传输特性,结果显示,器件的信道间隔为0.845 01 nm,插入损耗小于14 dB,串扰小于-25 dB。     

A novel asymmetric arrayed waveguide grating with different lengths of input/output slabs

A novel arrayed waveguide grating (AWG) with asymmetric configuration is proposed. In this configuration, the length of the output slab region, the width and the spacing of the output waveguides are unequal to the corresponding parts of the input ones. Compared to a conventional symmetric AWG, the asymmetric AWG proposed in this paper has a smaller size without degrading its performance The analytic method used in a conventional symmetric AWG is extended to the asymmetric AWG. A design example of an asymmetric AWG with low insertion loss, low channel crosstalk and wide bandwidth is presented.     

基于阵列波导光栅的智能服装人体测温解调系统研究

研究并实现了一种应用于智能服装中人体温度测量的阵列波导光栅解调系统。分析了系统的解调原理,搭建了光纤布拉格光栅解调实验平台,采用了强度法解调出光纤光栅的布拉格波长,完成了光纤光栅传感器串联前后解调的实验。结果表明,系统对光纤布拉格光栅的布拉格波长的解调具有高线性度,波长测量精度可达0.001 nm,光纤布拉格光栅传感器间串扰所造成的解调误差为0.000 5 nm,人体温度的测量误差为±0.16 ℃。该解调系统精度高、串扰低,可适用于智能服装中人体温度的测量。     

A 32-channel 100 GHz wavelength division multiplexer by interleaving two silicon arrayed waveguide gratings

A 32-channel wavelength division multiplexer with 100 GHz spacing is designed and fabricated by interleaving two silicon arrayed waveguide gratings (AWGs). It has a parallel structure consisting of two silicon 16-channel AWGs with 200 GHz spacing and a Mach-Zehnder interferometer (MZI) with 200 GHz free spectral range. The 16 channels of one silicon AWG are interleaved with those of the other AWG in spectrum, but with an identical spacing of 200 GHz. For the composed wavelength division multiplexer, the experiment results reveal 32 wavelength channels in C-band, a wavelength spacing of 100 GHz, and a channel crosstalk lower than -15 dB.     

光栅周期包含的Bragg层数对Bragg型凹面衍射光栅的影响

单个衍射光栅周期所包含的Bragg周期层数是连续Bragg齿型凹面衍射光栅的主要参数之一,该参数可改变光栅齿结构,对凹面衍射光栅的分辨力.自由光谱范围及衍射效率有重要影响.本文通过理论分析与仿真模拟,对比了4种不同层数的Bragg型凹面衍射光栅的特性参数.研究结果表明:在衍射光栅尺寸不变的情况下,改变单个光栅周期包含的Bragg周期层数不会显著提高器件主衍射级次的分辨力;单个光栅周期包含的Bragg周期层数与光栅可衍射的级次数成正相关.单周期层数的Bragg凹面衍射光栅的主衍射级次效率最高,其可衍射的级次数最少,且其他衍射级次分散的能量最少;增加单个光栅周期所包含的Bragg周期层数会降低主衍射级次的自由光谱范围.该研究对于设计低插损、高分辨率、宽工作波段的波分复用器或光栅光谱仪具有重要的指导意义.     

Performance analysis of metro WDM network based on an optical cross connects and arrayed waveguide grating demultiplexer

In this paper, we have demonstrated the quality-of-service offered by the metropolitan area network which is based on optical cross connect (OXC) and arrayed waveguide grating (AWG) demultiplexer operating at 10 Gb/s with 0.1 nm channel spacing for NRZ signal transmission. The data is successfully transmitted to a distance of 40 km with a reasonably good BER of 2.388 × 10⁻³⁵. The OXC and AWG demultiplexers in the proposed architecture allow incremental expansion in terms of the number of wavelength channels to be transmitted. Dispersion and crosstalk are the main signal-degrading factors arising from the operation of the OXC and the effectiveness of each factor is individually investigated.     

低插入损耗阵列波导光栅的设计

研究了阵列波导光栅的插入损耗.针对损耗来源,讨论了各项损耗的研究方法.分析了结构参量对损耗的影响,讨论了降低损耗的设计思路.对结构参量进行优化,设计了8通道200 GHz间隔的阵列波导光栅,中心通道插入损耗为1.37 dB,低于目前商用器件的1/2.对阵列波导光栅的设计具有一定的指导意义.     

聚合物费米型截面阵列波导光栅的优化设计

利用微扰理论给出“等效矩形波导法”,分析了费米型截面硅基聚合物阵列波导光栅的传输特性.模拟表明,波导的费米型截面将使阵列波导光栅的传输光谱产生漂移、并使串扰增大.为了消除光谱漂移、减小串扰、实现正常的解复用功能,对阵列波导光栅的结构参量进行了重新优化.结果表明,重新设计的费米型截面聚合物阵列波导光栅的光谱响应和串扰恢复到初始设计的聚合物矩形截面阵列波导光栅的水平.     

UV-written long-period waveguide grating coupler for broadband add/drop multiplexing

We demonstrate a UV-written polymer long-period waveguide grating (LPWG) coupler, which offers a bandwidth of ∼20 nm, a maximum coupling efficiency of ∼80% and ∼60% for the TE and TM polarizations, respectively, and a wavelength-tuning range over the (S + C + L)-band (∼140 nm) with a temperature control of ∼25 °C. The LPWG coupler has the potential to be developed into a practical broadband add/drop multiplexer for coarse wavelength-division-multiplexing applications.     

聚合物/二氧化硅混合型无热化阵列波导光栅参量的优化

研究一种新型无热化聚合物/二氧化硅混合波导组成的硅基二氧化硅阵列波导光栅.阵列波导光栅对温度的依赖性受波导物质的折射率和波导芯的尺寸影响.通过调节这些参量就可以减小温度对阵列波导光栅的影响.优化得到混合型阵列波导光栅在温度20~70℃范围内波谱漂移小于常规型 AWG结构的5%.     

低热应力热稳定曲线型阵列波导光栅复用器

相对方形阵列波导光栅波分复用器芯片而言,采用曲线切割的复用器芯片可以成倍地增加单个晶圆上的复用器产出率,但是曲线切割复用器的中心波长更加容易受到热应力的影响,该热应力是由于封装盒与耦合到复用器芯片上的带状光纤之间的线膨胀系数差异所引起的.本文实验分析了封装热应力对复用器中心波长的影响,结果表明,封装热应力与复用器中心波长之间的变化成线性关系.即使采用比较软的硅橡胶将复用器上的带状光纤固定到封装盒上,对于热稳定封装的曲线复用器而言,当环境温度在-20~65℃之间变化时,其中心波长也会有46 pm的变化.通过在热稳定复用器封装用的加热片上贴一片高硼硅玻璃,同时将带状光纤用硅橡胶固定到高硼硅玻璃上的方法,既保证了带状光纤相对封装盒固定,又减小了它们之间线膨胀系数不一致导致的热应力.实验结果表明,在-20到65 ℃温度范围内,这种复用器模块的中心波长高低温变化典型值小于5 pm,而且光纤所受的应力典型值小于0.029 MPa.