共查询到20条相似文献,搜索用时 31 毫秒
1.
Daoxin Dai Sailing He 《Photonics Technology Letters, IEEE》2008,20(8):599-601
This letter presents a design for diminishing the polarization-dependency of a Si nanowire-based multimode interference (MMI) coupler by using a tapered MMI section. The entrance width and waist width of the tapered MMI section are optimized to obtain a polarization-insensitive MMI length for N-fold self-imaging. The MMI section with a diminished polarization-dependency has a relatively large entrance width, which is beneficial to the separation of adjacent access waveguides for minimizing the coupling between them. One can tune the power splitting ratio of a 2 times 2 Si-nanowire MMI coupler by adjusting the entrance and the waist width of the tapered MMI section. 相似文献
2.
Jie Lin 《Photonics Technology Letters, IEEE》2008,20(14):1234-1236
An ultracompact polarization-insensitive 1times2 multimode interference (MMI) splitter based on silicon-on-insulator is investigated theoretically. The impact of the insulator index on the size of the MMI and the polarization-dependent performance is analyzed. A polarization-insensitive 1times2 MMI splitter of 4 mum by 16.5 mum is shown as an example. Relaxed tolerances on MMI width (> plusmn100 nm) and length (> plusmn0.7 mum) are obtained for both polarizations while the polarization differential loss is kept in range of 0.1 dB and its excess loss is kept below 0.5 dB. In addition, a wide operation wavelength window of 150 nm is obtained for both polarizations as well. 相似文献
3.
《Microwave Theory and Techniques》2005,53(8):2616-2621
This paper presents the design of lumped quadrature power splitters (LQPSs) based on unit cells of right-handed (RH) and left-handed (LH) synthetic transmission lines (TLs). The LQPSs include a lumped Wilkinson splitter, with phase-adjusting RH/LH TLs at the outputs. Two topologies, considered to be advantageous with regards to size and electric characteristics, are studied in detail. For these two, closed-form design equations are derived and the performances are analyzed by circuit simulations. The theory and simulation results are experimentally validated by monolithic-microwave integrated-circuit prototypes designed for a center frequency of 2.5 GHz. Both prototypes have performance that agree well with theory and design simulations. Within the frequency range of 2–3 GHz, the maximum amplitude and phase errors are less than 0.3 dB and 3$^circ$ , respectively. All reflections and the isolation are better than$-$ 10 dB. The effective areas of the two prototypes are 900$, times,$ 700$mu$ m$^2$ and 720$, times,$ 520$mu$ m$^2$ , respectively. 相似文献
4.
A polarisation-insensitive planar 980/1550 nm wavelength (de)multiplexing coupler based on multimode interference (MMI) effects is presented. The device is useful for integration with rare-earth doped waveguide amplifiers and lasers. The waveguide parameters and, in particular, the coupler width are chosen to optimise the device performance and obtain polarisation-insensitivity 相似文献
5.
Kim D.G. Oh G.Y. Choi W.K. Kim H.J. Kim S.H. Ki H.C. Kim S.T. Ko H.J. Kim T.U. Yang M.H. Dagli N. Choi Y.W. 《Electronics letters》2008,44(20):1192-1193
Novel triangular resonators containing active and passive sections have been fabricated and characterised with various multimode-interference (MMI) lengths. The optimum MMI length and width turn out to be 108 and 9 mm, respectively. A free spectral range of approximately 228 GHz is observed near 1558 nm along with an on?off ratio of 9 dB. The proposed triangular resonator has the advantage of removing the direct coupling between the two access waveguides of the MMI coupler. 相似文献
6.
Optimal design of an MMI coupler for broadening the spectral response of an AWG demultiplexer 总被引:1,自引:0,他引:1
Daoxin Dai Shuzhe Liu Sailing He Qincun Zhou 《Lightwave Technology, Journal of》2002,20(11):1957-1961
Optimal design of a multimode interference (MMI) coupler for broadening the spectral response of an arrayed-waveguide grating (AWG) demultiplexer is considered. By using a Gaussian beam approximation, an analytical expression for the spectral response of an AWG demultiplexer (with an MMI section) is obtained. A simple analytical formula is derived to relate the optimal MMI length to the separation between the peaks of the twofold images in the MMI region. This peak separation is related to the width of the MMI section. In the proposed design method, a required 1-dB passband width determines the peak separation, which then determines the optimal value for the length of the MMI section according to the analytical formula. The designed flat-top AWG demultiplexer is verified by the beam propagation method. 相似文献
7.
基于绝缘体上硅脊型纳米线光波导方向耦合器的TE/TM偏振分束器 总被引:1,自引:0,他引:1
利用有限元方法和时域有限差分方法,优化设计了一种结构紧凑的基于绝缘体上硅脊型纳米线光波导方向耦合器的TE/TM偏振分束器。考虑到方向耦合器的波导间隙较小时制作工艺较为困难,且模式失配会引入一些损耗,因此波导间隙取约100nm较为合适。通过优化脊型纳米线光波导的几何尺寸(脊高和脊宽)、耦合区波导间隙,使得偏振分束器长度最短。数值计算结果表明经过优化的偏振分束器最短长度大约为17.3μm,偏振分束器的消光比大于15dB时,波导宽度制作容差为-20~10nm,带宽约为50nm。 相似文献
8.
De Merlier J. Morthier G. Verstuyft S. Van Caenegem T. Moerman I. Van Daele P. Baets R. 《Photonics Technology Letters, IEEE》2002,14(5):660-662
A novel all-optical 2R regenerator based on a multimode interference coupler (MMI) semiconductor optical amplifier is presented. Static measurements of the transfer function reveal a digital transfer characteristic and a high increase in extinction ratio. The experiments are in good agreement with simulations, which have been done using a modified beam propagation method program. The device has a high tolerance to the MMI length. It has been fabricated in an all-active layout, avoiding the need for active/passive integration and is very compact 相似文献
9.
The design of an ultra-compact SOI-based 1×2 3 dB multimode interference(MMI) coupler is proposed.The symmetric multimode interference structure and deeply-etched parabolically tapered multimode waveguide are used in the device.The length of the device is reduced by about 87% compared with general multimode interference straight couplers.Based on effective index method(EIM) and two dimensional beam propagation method(2D-BPM),the structure parameters are optimized and the fabrication tolerances are analyzed.The results indicate that the performance of the coupler is deeply affected by the coupler's width,etching depth and photolithography alignment error in perpendicular direction. 相似文献
10.
设计蝶形多模干涉(MMI)耦合器时,需要根据所要求的功率分割比率确定器件的结构参量。作为矩形多模干涉耦合器的特征参量的耦合长度,通过数值分析对称干涉型矩形多模干涉耦合器的成像位置而得到,从而可利用模传输分析(MPA)法的公式设计出蝶形多模干涉耦合器的理论预期结构。使用有限差分波束传输法(FD-BPM)对设计参量进行校正,并且数值算出器件实际实现的功率分割比率。针对基于SOI晶片的设计实例表明,仿真得到的蝶形多模干涉耦合器的长度较理论预期大2~4 μm,实际实现的功率分割比率较理论预期值低且器件形状越偏离矩形,其值相差越大。 相似文献
11.
《Photonics Technology Letters, IEEE》2008,20(17):1485-1487
12.
Jong‐Moo Lee Joon Tae Ahn Doo Hee Cho Jung Jin Ju Myung‐Hyun Lee Kyong Hon Kim 《ETRI Journal》2003,25(2):81-88
We designed a multimode interference (MMI) coupler to use in vertical coupling of double layered polymeric waveguides and analyzed the coupling characteristics by comparing our experimental and simulation results. We found that our proposed new structure, a stepped MMI coupler, is effective in vertical coupling between waveguide layers with a short length of MMI and has a high tolerance for the variation in the structure of an MMI coupler that can be induced as errors in the fabrication process. 相似文献
13.
Koonath P. Sangin Kim Woon-Jo Cho Gopinath A. 《Quantum Electronics, IEEE Journal of》2002,38(9):1282-1290
Theoretical modeling and fabrication of polarization-insensitive semiconductor optical amplifiers that use a multi-quantum-well structure as the gain media are reported. Polarization insensitivity of gain is achieved through the introduction tensile strain into the quantum wells. Gain calculations, using the k·p method, were performed to obtain the required amount of tensile strain to obtain polarization insensitivity over a wide energy spectrum. Fabricated amplifiers show a polarization-insensitive (<1 dB) spectral width of 10 nm at 1300 nm in the InGaAsP/InP system, 15 nm at 1300 nm in the AlInGaAs/InP system, and 40 nm at 1550 nm in the AlInGaAs/InP system 相似文献
14.
《Photonics Technology Letters, IEEE》2009,21(22):1698-1700
15.
Bukkems H.G. Strijbos R.C. Binsma J.J.M. de Vrieze H. Larson M.C. Smit M.K. Bente E.A.J.A. Verbeek B.H. 《Quantum Electronics, IEEE Journal of》2007,43(7):614-621
This paper introduces a novel integrated widely tunable laser, the tunable multimode interference (T-MMI) laser, with as tunable component an MMI coupler with a wavelength adjustable transmission spectrum. Experiments demonstrate up to 150 nm of tuning range for the T-MMI component and operation of a widely tunable T-MMI laser is demonstrated over a wavelength range of 38 nm. 相似文献
16.
《Electronics Packaging Manufacturing, IEEE Transactions on》2006,29(3):163-171
This paper conducts experimental and numerical investigations into the microforce probing technique used to test the functionality of IC devices. The study commences by considering the case of a single tungsten needle probe and examines the relationship between the contact force and the scrub mark size on aluminum pads at various levels of overdrive and shooting angle. Subsequently, a three-dimensional computational model is developed to facilitate the design of an optimum multilayer needle card layout. The simulation results obtained for the profile and size of the scrub marks on the upper surface of the aluminum pads of an IC device are found to be in good agreement with the experimental observations. The validated model is then applied to analyze the effects of the tip length and beam length on the scrub mark profile and the stress distribution contours within the needle during a wafer level test. The results predicted by the finite-element model (FEM) for the scrub mark length under various beam lengths are used to specify a suitable design for a multilayer needle layout. Taking the case of DDR2 SDRAM of an aluminum pad of dimensions 70$mu$ m$,times,$ 70$mu$ m (length by width), the numerical results enable appropriate values to be assigned to the shooting angles, beam lengths, and tip lengths of the individual needles within a four-layer probe card. 相似文献
17.
A wavelength multiplexer or demultiplexer plays ani mportant role in all wavelength division multiplexing( WDM) system.Silica-basedarrayed waveguide gratings(AWGs) offer attractive featuresinthis area due to theadvantage of large output channels and lowlo… 相似文献
18.
《Photonics Technology Letters, IEEE》2008,20(17):1464-1466
19.
Hongzhen Wei Jinzhong Yu Zhongli Liu Xiaofeng Zhang Wei Shi Changshui Fang 《Lightwave Technology, Journal of》2001,19(5):739-745
Analytical expression of signal bandwidth of general straight and tapered N×N multimode interference (MMI) couplers is presented. The signal bandwidth is characterized as a function of mode relative energy, mode propagation delay time, and mode pulse broadening in the multimode section of MMI coupler. The model is used to evaluate the signal bandwidth of specific couplers. Results indicate that the signal bandwidth decreases seriously with the increase of channel number and channel guide space. Compared with the straight MMI coupler, the tapered MMI coupler has an improved signal bandwidth 相似文献
20.
The temperature dependence of characteristics for multimode interference (MMI) based 3-dB coupler in silicon-on-insulator is analyzed, which originates from the relatively high thermo-optic coefficient of silicon.For restricted interference 3-dB MMI coupler,the output power uniformity is ideally 0 at room temperature and becomes 0.32 dB when temperature rises up to 550 K.For symmetric interference 3-dB MMI coupler,the power uniformity keeps ideally 0 due to its intrinsic symmetric interference mechanism.With the temperature rising,the excess loss of the both devices increases.The performance deterioration due to temperature variety is more obvious to restricted interference MMI3-dB coupler,comparing with that of symmetric interference MMI3-dB coupler. 相似文献