美国物理学家表示，他们探索出了一种探测电流的新方法。这一方法基于二次谐波产生的过程，就像一个能远程监控电子速度的“雷达测速仪”一样，能直接“看”到电子的运动并测出电子的速度。相关研究论文发表在《物理评论快报》杂志上。 美国堪萨斯大学的物理学助教赵辉（音译）和教授朱迪·吴等人在超快激光实验室进行了这项实验。他们发现，高能激光器发出的光照射在一种包含有移动电子的材料上时，会产生不同颜色的光。在实验中，他们仔细研究了纤薄的砷化镓晶体材料，该材料广泛应用于高速电子学和高速光子学。通过朝整块晶体施加电压，他们让电子以特定的速度在晶体内流动。用人眼看不见的红外激光脉冲照射该晶体，会产生人眼可见的红光，这正是二次谐波产生过程出现的信号。 他们还发现，红光的亮度与电子的速度成比例，也就是说电子运动速度越快，红光越亮；而当电子没有直接运动时，没有红光出现。赵辉表示：“通过探测红光，我们能精确测量电子的速度，电子不需要同其他样本接触；我们也不会干扰电子的活动。在此项研究之前，现有探测实验技术都基于电流有三个效应：它能为系统充电、改变系统的温度并产生磁场。而科学家最新发现，电流还具有光子效应，这种使用激光研究电流的新方法完全基于这一最新效应。” 研究人员表示，新方法有望改善现今的很多可再生能源技术，诸如太阳能电池、人工光合作用以及水分解等，因为这些技术都依靠对电流进行探测。而且，能更好“阅读”电子运动的传感器可能会成为下一代手机和计算机的基础。 论文摘要： Second-Harmonic Generation Induced by Electric Currents in GaAs We demonstrate a new, nonlinear optical effect of electric currents. First, a steady current is generated by applying a voltage on a doped GaAs crystal. We demonstrate that this current induces second-harmonic generation of a probe laser pulse. Second, we optically inject a transient current in an undoped GaAs crystal by using a pair of ultrafast laser pulses and demonstrate that it induces the same second-harmonic generation. In both cases, the induced second-order nonlinear susceptibility is proportional to the current density. This effect can be used for nondestructive, noninvasive, and ultrafast imaging of currents. These advantages are illustrated by the real-time observations of a coherent plasma oscillation and spatial resolution of current distribution in a device. This new effect also provides a mechanism for electrical control of the optical response of materials.
from: http://blog.sciencenet.cn/home.php?mod=spaceuid=39812do=blogid=209592 超短脉冲激光器从上世纪80年代开始，经历了从染料到固体飞秒激光器的发展，开辟了科学和工业应用的新时代。但其昂贵的价格，庞大的体积，对环境的稳定性差等缺陷阻碍了飞秒激光的应用。探索新机理，突破现有飞秒激光局限，研制新一代飞秒激光成为世界范围内热门研究课题。自90年代初，光纤激光器利用半导体激光器泵浦，具有小巧、结构简单、无需水冷和可集成化的特点，逐步发展起来并成为钛宝石激光器强有力的竞争者和替代者 。早期的飞秒光纤激光器，采用掺铒的通信光纤，工作波长1550nm，普通单模光纤色散为负，能提供与自相位调制对应的啁啾补偿，于是孤子锁模(Soliton mode locking) 和展宽脉冲(Stretched pulse) 锁模就成为主流机制。由于其倍频光的波长在775nm，经过拉曼移频可移到800nm附近，在商用激光器上，已经用作钛宝石放大器的种子脉冲 。但是，由于铒光纤的掺杂浓度不能很高，以及锁模机制的限制，输出脉冲能量仍然很低（10pJ-10nJ量级），限制了此种光纤激光器的应用。进入新世纪后，随着高掺杂掺镱光纤激光器的发展，自相似(Self-similar) 和全正色散(All-normal-dispersion) 锁模理论被提出并在实验上获得证实，使光纤振荡器的单脉冲能量突破10nJ 。 与其平行的是，90年代中期光子晶体光纤的问世，使得飞秒光纤激光器多了一个选择支 。光子晶体光纤的主要特点是大模场面积光纤比普通的双包层光纤能更好地保持单模特性，在放大器上有重要应用。但是，光子晶体增益光纤特别是双包层大模场面积光子晶体光纤价格非常昂贵，远远高于晶体的价格；而且泵浦光的耦合需要在空间进行，对机械件稳定性能要求很高，不像普通单模光纤以及普通的双包层光纤有直接的光纤合成。进一步来说，大模场面积光子晶体光纤的可弯曲程度很差，甚至变成了光纤“棒”(Rod-type)，丧失了光纤原有的柔韧特性，反而使其体积大于同类固体激光放大器。 对于工作在1微米波段的光子晶体光纤，不同于普通的单模光纤，可以提供负色散，但也仅仅限于光纤芯径在1~2微米的光纤。在这样细的光纤中，孤子能量非常小，否则就会导致脉冲分裂，也不可能作为放大后的压缩器。由于以上缺点，除了放大器，光子晶体光纤做飞秒激光器振荡器并无明显优势。目前国内外报道的光子晶体光纤激光器，都是空间耦合的，并含有光栅对等需要空间的元件，不是低成本、抗击外部环境影响的封闭式结构。飞秒光纤激光器的低成本不是光纤本身成本低，而是半导体泵浦激光器的成本低。光纤激光器本身，无论是普通单模光纤，还是光子晶体光纤，都远比固体激光器贵。掺杂的光子晶体光纤价格更是比普通单模光纤高，比如一根大模场面积光纤“棒”的价格为数千欧元。 光纤激光器的最大优点是小型化、封闭式及无水冷。如果反过来做成空间式的，那就只有效率高这样的优点，稳定性甚至不如固体激光器。因此，作为放大器的种子光源以及对小能量应用（脉冲能量小于1mJ，例如光波导的刻划、THz波的产生、精密时频传输、纠缠光子对的产生、泵浦探针测量等），普通单模光纤飞秒激光器以及普通大模场面积光纤飞秒放大器依然发挥着不可取代的作用。著名的康奈尔大学和麻省理工学院研究小组，在光纤激光器的研究中，仍然把普通单模光纤激光器作为主要研究方向。其主要的光纤激光器创新理论和实验，都是在普通单模光纤激光器中完成的。 北京大学近两年来在863、支撑项目等课题的支持下，开展了飞秒光纤激光器的研究，取得一系列重要成果。主要成果包括：①半导体可饱和吸收镜的研制成功；②碳纳米管锁模成功；③新激光器腔型的创新；④超长腔锁模获得高能量脉冲输出成功等。 1、半导体可饱和吸收镜（SESAM）不仅是飞秒脉冲固体激光器的核心器件，也是飞秒脉冲光纤激光器的核心器件。不同的是，在固体激光器应用中，要求SESAM的调制深度比较低（1~2％）。而光纤激光器的锁模则需要20~30％甚至50％的调制深度。根据光纤激光器的需要，我们设计和制作了适合掺铒和掺镱光纤飞秒激光器锁模的SESAM。我们设计了若干调制深度的SESAM，包括镀保护膜的SESAM。对于应用于掺铒光纤激光器的SESAM，会有严重的晶格失配问题。我们用在晶格匹配的基片生长吸收层和间隔层，在其上镀介质膜和金属膜作为反射镜，然后将基片衬底腐蚀掉的技术，首次研制成功高调制深度的掺铒光纤用SESAM （图1(a)）。对于掺镱光纤飞秒激光器，由于砷化镓基片与吸收材料铟镓砷的晶格有失配，若吸收层超过临界厚度，会发生位错等缺陷，导致损伤阈值的降低。我们采用了缓冲层的方法，有效地抑制了由于晶格失配导致的生长缺陷以及由此导致的损伤阈值的降低（图1(b)）。为了测量其饱和恢复时间，我们设计了专用的Pump-probe装置。测量表明，我们研制的SESAM饱和恢复时间短只有不到2ps。所有SESAM都在光纤激光器上锁模成功。这标志着我国已经完全能够生产这两种激光器所需要的SESAM。 2、除了SESAM，新世纪以来，一种新型的锁模器件：单壁碳纳米管可饱和吸收器(CNT-SAM) 诞生并成为固体和光纤激光器的新宠。我们首先利用光学梯度力将CNT生长的光纤接头上，成功获得锁模；由于这种生长方式生长的CNT极易损坏，我们利用清华大学提供的新的单壁CNT薄膜结合在反射镜上，制成掺铒光纤激光器用的CNT-SAM，其特点是饱和恢复时间短(2ps)，易于集成化。在掺铒光纤激光器中实验表明，用CNT-SAM的光纤激光器锁模阈值低，非常适合高重复频率和低泵浦时的应用，在光纤频率标准和时频传输方面将发挥核心作用。 3、新型光纤激光器。利用我们研制的SESAM和CNT-SAM，我们试验了各种腔型。无论是线性腔，还是环形腔，无论光纤多长，都可以用SESAM或CNT-SAM实现锁模。但是在环形腔内如何装着SESAM或CNT-SAM是个问题。不少激光器把可饱和吸收器放在光栅对后面，并用透镜聚焦在SESAM上。这样做的最大问题是，由于波长分量顺序的反转，返回光的光束变大，不能完全耦合入光纤，导致损耗和光谱滤波效应。为了把我们研制的SESAM用在环形腔光纤激光器上，并同时装有光栅对，我们发明了一种新的腔型，同时装有SESAM和光栅 。此谐振腔克服了在光栅对后加SESAM的光谱限制作用，既能够实现锁模自启动，又能保证锁模带宽。 4、超长腔光纤激光器。飞秒激光器的很多应用并不需要几十MHz的重复频率，最适合微细加工领域应用的是100kHz－500kHz重复频率，mJ量级的脉冲能量。为了在飞秒光纤激光器直接中获得超高能量的脉冲，我们提出了超长腔的光纤激光器的想法，这个想法与康奈尔大学研究者的想法不谋而合。我们试验了从400m到2km长的光纤谐振腔。这样的长腔全正色散激光器，即使采用全正色散光纤中必要的光谱滤波器，用非线性偏振旋转机制锁模已经非常困难。因此SESAM起了决定性作用。如此长腔的激光器，输出脉冲能量大大提高。以400m腔长的掺镱光纤激光器为例，在300mW泵浦下，输出脉冲能量高达320nJ，一次放大后脉冲能量超过4mJ 。而对铒光纤激光器的几十nJ的输出，一次放大就达到790nJ 。由于重复频率从几十MHz降低到380kHz ，已经可以直接应用于微细加工等。这种超低重复频率的激光振荡器在固体激光器中是很难实现的，而在光纤激光器中相对容易。这种激光器作为放大器的种子光源，节省了脉冲选单器（普克尔盒、声光调制器）、光纤展宽器和前级放大器等，具有非常大的应用价值。此技术已经申请了专利。 飞秒光纤激光器已经发展了近20年，仍然不断有新的概念和新的器件创出。如果没有先进的理念，没有自己的创新器件，我国在这个领域将永远处于劣势地位。某些光纤激光器国外对我国禁运就是例证。研制自己的核心元器件，并在此基础上研制自己的飞秒光纤激光器整机，不但是创新的基础，也是产业化的基础。幸运的是，北京大学研究小组已经在某些核心元器件和整机方面赶上了国际先进水平，并有所创新。我们将继续研制新型元器件和新型光纤激光器，使我国在光纤激光器领域内的竞争中占有一席之地。 参考文献： K. 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PCF和特殊光纤传感器的报道仍比较多。 台湾的 C.-f. Fan 等人提出了利用 PCF 环的双折射特性进行横向位移传感的方法（ "Birefringent photonic crystal fiber coils and their application to transverse displacement sensing," Opt. Express , vol. 19, pp. 19948-19954, 2011. ）。 图 1 基于 PCF 环的横向位移传感 香港理工的 C. Wu 等人提出了用聚酰亚胺涂覆的 PCF 测量盐度的方法（ "Salinity sensor based on polyimide-coated photonic crystal fiber," Opt. Express , vol. 19, pp. 20003-20008, Oct 2011. ）。 哈尔滨工程大学的 C. Y. Guan 等人研究了一种“埋入纤芯”的空心光纤特性（ "Characteristics of embedded-core hollow optical fiber," Opt. Express , vol. 19, pp. 20069-20078, Oct 2011. ）。 图 2 “埋入纤芯”的空心光纤 墨西哥的 G. A. Cardenas-Sevilla 等人报道了利用 PCF 干涉仪进行折算率传感（ "High-visibility photonic crystal fiber interferometer for ultrasensitive refractometric sensing," in Proc. of SPIE Vol. 8011 , 2011, p. 80114K. ）。 图 3 利用 PCF 干涉仪进行折算率传感 葡萄牙的 L. Bilro 等人报道了采用侧抛塑料光纤（ POF ）进行折射率和弯曲传感（ "Analytical Analysis of Side-Polished Plastic Optical Fiber as Curvature and Refractive Index Sensor," JOURNAL OF LIGHTWAVE TECHNOLOGY , vol. 29, pp. 864-870, Mar 2011. ）。 图 4 侧抛塑料光纤（ POF ） 比利时的 T. Baghdasaryan 等人研究了不同写入角度对纯硅材料 PCF 写入 FBG 的影响（ "Influence of Fiber Orientation on Femtosecond Bragg Grating Inscription in Pure Silica Microstructured Optical Fibers," Photonics Technology Letters, IEEE , vol. 23, pp. 1832-1834, 2011. ）。 图 5 不同写入角度下的 FBG 谱 上海交大的 X. S. Liu 等人提出了一种基于 LPG 的多波长可调谐光纤激光器（ "Individually Switchable and Widely Tunable Multiwavelength Erbium-Doped Fiber Laser Based on Cascaded Mismatching Long-Period Fiber Gratings," JOURNAL OF LIGHTWAVE TECHNOLOGY , vol. 29, pp. 3319-3326, Nov 2011. ），有望用于传感光源。 图 6 多波长可调谐激光器 墨西哥的 K. M. Salas-Alcantara 等人发表了采用两个 LPG 进行横向位移测量的方法（ "Micro-displacement sensor using a Mach-Zehnder interferometer with long-period gratings," in Proc. of SPIE Vol. 8287 , Toluca de Lerdo, Mexico, 2011, pp. 82870Z-6. ），其中 LPG 采用机械应力的方法制得。 图 7 双 LPG 测量横向位移 墨西哥的 V. Salazar-Haro 等人报道了利用光纤端面反射进行液体分析（ "Liquids analysis using back reflection single-mode fiber sensors," in Proc. of SPIE Vol. 8011 , 2011, p. 80114W. ）。 哥伦比亚的 L. A. D. Marulanda 等人报道了利用光纤传感器进行石油掺杂检测（ "Measurement of gasoline adulteration using optical fiber sensor," in Proc. of SPIE Vol. 8011 , 2011, p. 80115B ）。 波兰的 M. Zyczkowski 等人进行了用光纤干涉仪进行心跳监测的试验（ "Interferometric Fiber Optics Based Sensor for Monitoring of the Heart Activity," Acta Physica Polonica A , vol. 120, pp. 782-784, Oct 2011. ）。 墨西哥的 V. I. Ruiz-Perez 等人报道了利用多模干涉方法测量压力（ "Multimode interference effects in optical fiber for pressure sensing applications," in Proc. of SPIE Vol. 8011 , 2011, p. 80115M. ）。 浙江大学的 D. Chen 等人提出了用少模光纤的模间干涉测量压力的方法（ "HYDROSTATIC PRESSURE SENSOR BASED ON MODE INTERFERENCE OF A FEW MODE FIBER," Progress in Electromagnetics Research-Pier , vol. 119, pp. 335-343, 2011. ）。 以色列的 Y. Peled 等人提出了基于受激布里渊散射的光纤应变检测方法（ "Slope-assisted fast distributed sensing in optical fibers with arbitrary Brillouin profile," Opt. Express , vol. 19, pp. 19845-19854, Oct 2011. ）。 日本的 M. Nakano 等人报道了利用 BOTDA 进行隧道监测（ "Structure monitor system by using optical fiber sensor and watching camera in utility tunnel in urban area," in Proc. of SPIE Vol. 8011 , 2011, p. 80116N. ）。 南京大学的 L. Gao 等人提出了采用光纤激光器同时测量应变和载荷的方法（ "Simultaneous Measurement of Strain and Load Using a Fiber Laser Sensor," Sensors Journal, IEEE , vol. PP, pp. 1-1, 2011. ）。其原理是利用纵模的排频和偏振模的排频对应变和载荷的灵敏度不同。 图 8 利用 FL 进行应变和载荷的同时测量 墨西哥的 D. Monzon-Hernandez 等人提出了用两个光纤拉锥进行弯曲传感的方法（ "Compact optical fiber curvature sensor based on concatenating two tapers," Opt. Lett. , vol. 36, pp. 4380-4382, 2011. ），其原理是光在两个拉锥区域纤芯模和包层模的干涉。可通过改变拉锥的直径和两个拉锥的间距改变动态范围。 图 9 在 两个拉锥区域纤芯模和包层模的干涉 日本 Tokyo Medical and Dental University 的 H. kudo 等人报道了光纤甲醛传感器（ "Fiber-optic biochemical gas sensor (bio-sniffer) for sub-ppb monitoring of formaldehyde vapor," Sensors and Actuators B: Chemical . ）。 南通大学的 G. Lu 等人报道了利用光纤光栅进行复合材料低速撞击的能量分级试验（ "The Energy Class Discrimination of Low Velocity Impacts on Composite Material Structure by Bragg Grating Sensor Technique," Composites Part B: Engineering . ），试验以一个摆球从不同角度落下撞击聚合物材料（内含 5 个 FBG ）的方法进行。通过对采集到的 FBG 波长漂移的频谱进行分析，可得到不同撞击情况下能量在频谱上的分布，从而进行撞击能量的分级。 英国 Strathclyde 大学的 P. Orr 等人报道了采用光开关进行高速 FBG 解调的方法（ "High-Speed, Solid State, Interferometric Interrogator and Multiplexer for Fiber Bragg Grating Sensors," JOURNAL OF LIGHTWAVE TECHNOLOGY , vol. 29, pp. 3387-3392, 2011. ）。该方案仍采用干涉式解调，但通过高速的光开关切换不同的通道，从而保证解调速度的情况下保持很低的串扰。文章报道了在 4 kHz 下 3 支传感器复用的结果。 图 10 采用光开关进行高速 FBG 解调系统
A.J. Liu, et al., "Single-mode holey vertical-cavity surface-emitting laser with ultra-narrow beam divergence", Laser Phys. Lett., 7, No. 3, 213–217 (2010) / DOI 10.1002/lapl.200910130. 2010_LPL_Single-mode holey vertical-cavity surface-emitting laser with ultra-nar.pdf ( Laser Phys. Lett. 2009的影响因子为5.502) 在这篇文章中，我设计并制作了 花瓣孔状垂直腔面发射激光器，构成花瓣形结构的各楔形孔经过干法刻蚀后，沿着径向方向的刻蚀深度渐变。因此我们提出了渐变折射率模型构建孔区的折射率分布，成功解释了花瓣孔状垂直腔面发射激光器的多模低发散角特性。同时我们采用损耗机制解释了花瓣孔状垂直腔面发射激光器的单模特性。 两篇引用我的文章分别为： 1 Y. Q. Hao， et al., "High Power 808 nm Vertical Cavity Surface Emitting Laser with MultiRingShapedAperture Structure", DOI: 10.1134/S1054660X11030030 2011_LP_High power 808 nm vertical cavity surface emitting laser with multi-ring.pdf 2 W. NAKWASKI, "VCSEL structures used to suppress higher-order transverse modes", OPTO−ELECTRONICS REVIEW, 19(1), 119–129, 2011. DOI: 10.2478/s11772−010−0075−y 2011_VCSEL structures used to suppress higher-order transverse modes.pdf 它是一篇综述文章，把我的这篇文章提到的结构以及模型原理作为一种单独的器件结构以一段的篇幅（153个单词）予以了详细的介绍。 如下：“ Similar to the above is the VCSEL with the petal−shaped holey structure . As previously, increased scattering losses of higher order modes, as compared with that of the fundamental mode, are achieved in the petal holey structure with the larger hole number. Then, about 1 mW of the SFM output is achieved in the above 6−μm VCSEL emitting the 850−nm radiation (line 42). Relatively low output is a result of high optical losses introduced by the mode discrimination mechanism, surprisingly high as com− pared with the previous similar structure. However, divergence of the output beam of this device is very low (3.2°) which results from enlarged lateral dimension of the hole along the radial direction outwards from the centre , so the hole depth is gradually increased. Resulting graded index profile in the top DBR broadens the optical field which leads to this ultra−narrow beam divergence . ” 文章作者W. NAKWASKI介绍： Professor W. Nakwaski, the director of the Institute of Physics at the Technical University of Lodz, Poland , is an internationally recognized scientist working over 25 years in semiconductor optoelectronics . He has received MSc in both Electrical Engineering (in 1971 from the Technical University of Lodz) and Physics (in 1973 from the Lodz University), PhD and DSc in Electrical Engineering (in 1976 and 1985, respectively, from the Institute of Electron Technology in Warsaw) and the Title Professor in Physics (in 1996 from Aleksander Kwasniewski, the President of Poland). Being both the physicist and the electrical engineer, Professor W. Nakwaski is using in his research modern methods of computer physics to investigate performance of various optoelectronic devices, mostly semiconductor diode lasers. In particular, he has been simulating operation of various diode lasers and laser arrays in full complexity of all interrelated physical phenomena crucial for their proper work. Using the above simulations, he has been investigating an impact of various construction parameters on laser important performance characteristics, receiving essential optimization suggestions for laser designers. He has published his research results in over 300 regular and conference papers . He is also an co-author of two scientific books devoted to physics of semiconductor lasers , three chapters in scientific books and two patents. Professor W. Nakwaski has spent over 4 years in the Center for High Technology Materials at the University of New Mexico, Albuquerque, USA (1 year as a Senior Visiting Scientist and over 3 years as a Research Associate Professor). Now he is a Full Professor in the Institute of Physics, Technical University of Lodz, Poland and is supervising the Laboratory of Computer Physics at this institute.. Professor W. Nakwaski received 7 times (in 1978, 1980, 1984, 1987, 1990, 1999 and 2002) the Prize of the Minister of National Education in Poland for scientific achievements. 有点惊讶，因为对这个工作没有太多的期望...
Please browse http://www.oedcad.com/index.htm If you need the following software please fill the form ,then send the form and registerinfo.dat file toDr. Zhang Yejin Email: yjzhang@semi.ac.cn . Registerinfo.dat file can be generated by register.exe ofmenu after finishing installing module package. How to use these software s? Tel：086-010－82304760,086-13661385034 We can help you build your own optoelectronics device and optical fiber communication simulation platform, using the platform you can develop new arithmetic, new program. We can provide VC or fortran source code. Immediately your group will become stronger. Our program is designed according to commercial software standard. immediately NEW!!! 1.Parallel Cluster finite difference in time domain software (PCFDTD 1.22) 1) Supporting lossy , dispersive , nonlinear and active media for 1D,2D and 3D parallel FDTD simulation. 2) Supportingimporting any picture into software,such as SEM picture, and have a simulation or measurement for duty ration.Using the PCFDTD,you can obtain the characteristics of real device,such as photonic crystal slab,fiber and so on. 3) PCFDTD has friendly interface and can be used to edit any complex 1D 2D and 3D structure. It can simulate Photonic crystal slab, fiber, plasma, DFB,DBR laser,and so on. 4) Any shape topology optimization is developed for obtain good device performance,such as bend waveguide,laser, passive and active photonic or optical device. 5) Supporting large scale parallel cluster calculation and no processes number is limited. 6) Carrier rate equation is introduced FDTD simulation for process active device,such as DFB laser,SOA. 7) Single and double precision calculation is supported and unlimited continuous calculation is supported. 1D,2D and 3D figure output are supported. 8) Any direction near field ,far field, mode volumn can be calculated easily using the PCFDTD. 9) Pade approximation is introduced for signal processing,from which you can save 5-10 times CPU time for simulation cavity or obtaining frequency spectrum characteristics. 10) FDM (filter diagonalized method) also is introduced for process short signal. 11) FFT,DFT are used to analyze time domain signal. 12) Transfer matrix method (TMM )is supported to simulate energy band,photonic band structure and dispersive relation. Transmission and reflection spectrum can be easily obtained from TMM. In PCFDTD, solar cell efficiency also can be obtained and silicon and III-V compound material is both supported. DetailsDownload: Parallel Cluster FDTD suite 1.22 2.PCF(photonic crystal fiber design) Photonic crystal fiber (PCF) or microstructure optical fiber (MOF) design software is presented on the website. The software can process a SEM picture of PCF or MOF. The user can simulate the practicality .Therefore a comparison can be done between theory and experiment. Features: 1)Any kinds of photonic crystal fiber,Bragg fiber,hollow fiber, photonic gap fiber can be simulated. 2)Multiple pole method is developed for a presice simulation,such leakage/confinement loss of fiber. 3)Finite difference in frequency domain with PML(perfect matched layer) absorption boundary condition method is developed . 4)TMM(Transfer matrix method) is developed for a Bragg fiber. 5)An experimental fiber section (such as, SEM picture ) can be imported into this module for a simulation. 6)Quasi-FDTD is developed for simulating the fiber in time domain. 7)PWE(plane wave extension) method is developed for fiber band structure calculation. 8)This module have some application port for simulation using beam propagation module and FEM module. 9)Many fiber's characteristics can be simulated ,such as bend loss, leakage loss, splicing loss ,effective mode area ,dispersion relation ,mode distribution,V parameter,Gama parameter,and so on. 10)Optimized calculation can be executed with all kinds of scanning parameter. Details DOWNLOAD: PCF design system Plane Wave Extension Method for photonic crystal
标签: 激光器
