共查询到20条相似文献,搜索用时 15 毫秒
1.
为实现模块化相对论速调管放大器功率、频率和相位的在线测量,对紧凑型高定向性高带宽的定向耦合器进行了仿真和实验研究。利用小孔耦合理论和相位叠加原理进行理论分析,设计了一种双孔紧凑型定向耦合器,在此基础上采用主、副波导正交连接,耦合孔沿轴向和角向二维分布的方法,进一步缩短了耦合器的长度。通过电磁仿真对耦合器各参数进行优化,模拟结果表明:当中心频率为10 GHz时,普通双孔定向耦合器对TM01模式的耦合度为-60.68 dB,在250 MHz的带宽内定向性大于20 dB,此时耦合区长度为3.49 cm。改进型定向耦合器对TM01模式的耦合度为-58.1 dB,在300 MHz的带宽内定向性大于20 dB,此时耦合区长度仅为1.8 cm(约0.6λ)。耦合器的冷腔实验测量结果与仿真结果符合较好。 相似文献
2.
We propose and experimentally demonstrate a novel subwavelength grating coupler on silicon-on-insulator, for coupling to optical fibers with a wide optical bandwidth. Theoretical analysis and design optimization of the coupler are described. About 73?nm 1?dB bandwidth was experimentally demonstrated with -5.6 dB coupling efficiency. Better than -3.4 dB efficiency with 86?nm 1?dB bandwidth is predicted for these structures with optimized buried oxide thickness. 相似文献
3.
P.P. Sahu 《Optics Communications》2007,277(2):295-301
In this paper, a novel MMI coupler, based on general interference, with tapered waveguide geometry has been proposed for reduction of coupling length. The coupling characteristics and power imbalance of the proposed structure are compared with conventional MMI structures by using a mathematical model based on sinusoidal modes. It is seen that the beat length for tapered MMI coupler with angle of taper ∼1.05° is reduced by ∼24% of that of conventional MMI coupler and the coupling characteristics obtained with the mathematical model, match well with those obtained by more sophisticated BPM computer aided design software. The power imbalance for tapered 3 dB MMI coupler is more sensitive to the wavelength than that for conventional 3 dB MMI coupler and variation of power imbalance with fabrication tolerance for both the MMI coupler is almost same. 相似文献
4.
A novel hollow-core tapered coupler has been theoretically designed and fabricated by fiber drawingmachine. The coupler's inner wall is coated with a polycrystalline GeO_2 film. The coupling loss ofhollow-core tapered coupler is about 0.2 dB. Hollow-core tapered coupler reduces the transmission loss ofhollow-core optical fiber(HCOF) by 0.5 dB/m, therefore the coupler is suitable for coupling high powerCO_2 laser in industrial application. 相似文献
5.
Acrylic-based asymmetric and variable couplers have been developed using a single structured Y-branch design with a high-index-contrast
waveguide taper and a void structure for fiber attenuation using the lateral displacement of two fibers. Device fabrication
is performed by producing the device structure on an acrylic block using a computer numerical control (CNC) machine tool.
The fabricated device has an excess loss of 5.85 dB, while the coupling ratios are 56.86 and 43.14% when the device is operated
as a 3 dB coupler. In the asymmetric coupler mode, the coupling ratio ranges from 44.84 to 8.01% for port 1 and 55.16 to 91.99%
for port 2. The excess loss of this device varies from 5.42 to 7.64 dB. In the variable coupler mode, the coupling ratio ranges
from 10.09 to 32.88% for port 1 and from 89.91 to 67.12% for port 2. The excess loss of the device varies from 5.85 to 8.49
dB. 相似文献
6.
7.
设计了一种用于测量V波段过模高功率毫米波源在线功率的选模耦合器。利用小孔耦合理论和微元法对菱形耦合缝隙进行了理论分析,采用两组相同的菱形耦合缝隙实现选模功能,缩短了耦合器长度,增加了工作带宽。采用数值模拟的方法对耦合器结构进行优化设计,模拟结果表明:在60 GHz频点处,TM01模耦合度约为50 dB,TM02模耦合度仅为75 dB,对TM02模的抑制度为25 dB;在500 MHz带宽内对TM02模的抑制度大于15 dB,1 GHz带宽内的抑制度大于10 dB,可满足工作于TM01模的V波段高功率毫米波测试需求。同时针对工作于高次模TM0n(n=2,3,4,)的器件设计了可抑制TM01模的耦合器,为高次模工作的高功率毫米波器件的在线功率测量和模式诊断提供了技术方案。 相似文献
8.
F. Mattiocco 《International Journal of Infrared and Millimeter Waves》2003,24(7):1127-1131
The design of a 210-320 GHz multi-hole directional coupler is described. The coupler performance is measured with a millimeter vector analyser across the band 205-350 GHz and compared with simulations. The coupler consists of two waveguides whose broad walls are separated by a thin metal sheet with an array of circular holes according to a Chebyshev distribution of couplings. The coupling is 11 dB with a typical variation of ± 2dB across the WR3 band and the isolation is more than 25 dB. 相似文献
9.
介绍了大功率容量定向耦合器的设计、标定、测试与应用情况。以X波段圆波导定向耦合器为例,在9.2~10.2 GHz的频带范围内,基于小孔耦合理论优化设计的结构,其耦合度可以稳定在(55±2)dB以内,隔离度大于80 dB。在此基础上,设计加工了X波段圆波导定向耦合器并进行了标定测试,测试与仿真结果吻合较好,高功率微波实验证实了其具有较高功率容量,能够满足实验需求。该类圆波导定向耦合器已广泛应用于实验室高功率微波源的在线测量装置中。 相似文献
10.
提出了一种小型化双枝节加载的L波段微带线定向耦合器。使用功率相消技术提高定向耦合器的隔离度,并且采用两根长度不同的加载枝节分别在两个相近的频点上反射信号,从而实现耦合器的带宽扩展;同时采用缺陷地结构的慢波特性减小该定向耦合器的物理尺寸,并利用缺陷地结构产生的陷波,合并上述两根枝节反射抵消产生的的两个陷波,进一步提高定向耦合器的带宽和隔离度。该耦合器工作在L波段,耦合度约为10 dB,在整个L波段内的隔离度均优于?20 dB,最大约为?52.81 dB,相对带宽为60%。最后对设计的定向耦合器进行加工和测试,测试与仿真结果一致性较好,证明了该电路的可行性。 相似文献
11.
A novel grating coupler with a stair-step blaze profile is proposed.The coupler is a CMOS process compatible device and can be used for light coupling in optical communication.The blaze profile can be optimized to obtain a high efficiency of 66.7% for the out-of-plane coupling at the centre wavelength of 1595 nm with a 1 dB bandwidth of 41 nm.Five key parameters of the stair-step blaze grating and their effects on the coupling are discussed for the application in L band telecommunication. 相似文献
12.
Daniel Benedikovic Pavel Cheben Jens H. Schmid Dan‐Xia Xu Jean Lapointe Shurui Wang Robert Halir Alejandro Ortega‐Moux Siegfried Janz Milan Dado 《Laser \u0026amp; Photonics Reviews》2014,8(6):L93-L97
Grating couplers are key elements enabling the coupling of light between planar waveguide circuits and optical fibers. In this work, it is demonstrated using simulations and experiments that a high coupling efficiency can be achieved for an arbitrary buried oxide thickness by judicious adjustment of the grating radiation angle. The coupler strength is engineered by subwavelength structure, allowing straightforward apodization and single etch step fabrication. The design has been implemented using Fourier‐eigenmode expansion and finite difference time domain methods. The measured coupling loss of a continuously apodized grating is −2.16 dB with a 3 dB bandwidth of 64 nm, therefore opening promising prospects for low‐cost and high‐volume fabrication using 193 nm deep‐ultraviolet lithography. It is also shown by simulations that a coupling loss as low as −0.42 dB is predicted for a modified coupler structure with bottom mirror. 相似文献
13.
We design and fabricate an efficient broadband grating coupler on a 400 nm thick silicon-on-insulator wafer. The measured coupling loss is 3 dB when coupling to a single-mode fiber at 1310 nm wavelength with TE polarization. The spectral FWHM and backreflection are determined to be 58 nm and -27 dB, respectively. 相似文献
14.
本文设计并制作了基于强限制多模干涉耦合器的2×2 SOI马赫-曾德热光开关.这种光开关采用了深刻蚀结构的多模干涉耦合器和输入/输出波导,较大地提高了干涉耦合器的性能并减少了连接耦合损耗.同时,在调制臂区域采用浅刻蚀结构,保持其单模调制状态.深刻蚀多模干涉耦合器具有优越的特性,在实验中测得不均衡度只有0.03 dB,插入损耗-0.6 dB.基于这种耦合器的新型热光开关,其插入损耗为-6.8 dB,其中包括光纤-波导耦合损耗-4.3 dB,开关时间为6.8 μs. 相似文献
15.
16.
We design and demonstrate the fully-etched apodized grating couplers based on the silicon-on-insulator (SOI) platform using subwavelength structure for both transverse electric (TE) and transverse magnetic (TM) modes operation. The subwavelength grating (SWG) is used to engineer the refractive index using second-order effective medium theory (EMT). The whole designing procedure is given in details, especially a feasible and programmable method is developed to precisely manipulate the coupling strength of each grating cycle. A perfect Gaussian output beam can be synthesized for the TE mode operation, achieving a field overlap up to 98.3% with the Gaussian fiber mode. The simulated peak coupling losses are ?4.63 and ?2.99 dB for the TE mode and the TM mode, respectively, which are comparable with conventional shallowly etched grating couplers, realizing a fabrication simplification without performance penalty. The measured peak coupling loss is ?7.6 dB for the TE mode coupler with a 1 dB bandwidth of 45 nm, and ?6.1 dB for the TM mode coupler with a 1 dB bandwidth of 34 nm. 相似文献
17.
18.
输入耦合器是回旋行波管的重要组成部分之一,其作用是将矩形波导TE10模式的信号,通过模式变换结构转换为回旋放大器件中的模式,输入耦合器性能的优劣直接影响了回旋管整管的带宽等性能。通过对W波段TE02模式回旋行波管的输入耦合器进行理论分析,指出影响主模传输损耗的一个因素是杂模的崛起使主模的传输系数降低,利用仿真软件进行仿真,通过优化耦合孔的尺寸,抑制杂模的产生,将损耗从3.9 dB降低到了0.8 dB。根据优化尺寸加工,实际测试,得到3.0 dB带宽7.9 GHz的输入耦合器,与设计符合较好。 相似文献
19.
In this work we study the effect of radiation modes generated at the input of a directional coupler on its performance. We focus on the splitting ratio and the coupling length of the coupler. The Beam Propagation Method (BPM) is used for numerical simulation. Numerical results are compared to analytical expectations of the coupled mode theory (CMT). We show that, when the coupler is excited by a single mode fibre, ideal 3 dB couplers could be obtained by a simple adjustment of the exciting fibre. On the other hand, when the coupler has input and output bend structures, its coupling length as well as its splitting ratio are affected by the geometry of this bend. 相似文献
20.
We propose an efficient optical coupler between a submicrometer-sized silicon waveguide on a silicon photonic chip and a multi-micrometer wide polymer waveguide on an optical printed circuit board for interchip optical networks. We show low coupling loss <0.4 dB with high lateral and angular tolerance to misalignment so that coupling can be done by automatic pick-and-place equipments with high throughput and low cost. The coupler has a wide optical bandwidth from 1470 to 1650 nm. 相似文献