当初做这东西的时候,坦白说我是从弦论AdS/CFT去做这东西,因为都是自己做论文
不知道老板标准在那里不敢口试,转去超材料我完全不知道这在干嘛,后来一年了我渐渐
看出这里面的秘密了,每次遇到瓶颈和挫折,我就去超材料教皇ICL的 John Pendry和
Duke大学的D. R.Smith网站朝圣,我自己乱翻了一点超材料的历史,因为文章很长
我自己只是单据翻译并没有做整段的修饰,如果乡民觉得翻得不好请见谅,只是好玩和乐趣
当时已经没时间了,如果有兴趣的人可以帮我翻译得更好并且传阅这故事,希望台湾有一天
能够有真正科学传承,我相信诺贝尔物理奖提名者John Pendry和D. R.Smith能,我们也行!
这种算是一种凝态物理新兴领域,是属于那种数学很"简单"但是需要经验,巧思和创意的
http://people.ee.duke.edu/~drsmith/metamaterials/metamaterials_history.htm
超材料和负折射的故事：个人的角度
The Story of Metamaterials and Negative Index: A Personal Perspective
One of the questions I am often asked is how metamaterials first started.
Arguably, metamaterials is now a billion dollar enterprise, if you add up all
of the funding that has poured into metamaterials research and development
over the years. In addition, metamaterials has become one of the most exposed
if not overexposed areas of research, with the term "metamaterial" reaching
well into the popular media
我经常被问的其中一个问题是 超材料如何开始起源的。可以说，如果你加上大量
所有汇入超材料的研究和发展多年来的资金，超材料现在是一个数十亿美元的企业，。如
此之外，超材料已经成为曝光率最高的领域之一；即使不是曝光最高的领域，”超材料”
这个名词已经在大众媒体广为人知。
So, how did it all start?
Just as a matter of full disclosure, what I'm writing here is not an official
or comprehensive history. It's a history from my point-of-view, about what
was on my mind at the time and the events that happened to and around me. The
field of metamaterials has a lot of threads; I don't think anyone at this
point could recount a complete story of the development of the field, which
by now contains the contributions from thousands of researchers
那么，这一切是怎么开始的？
正如所公开的事实，我在写在这里不是官方的或全面性的历史。这是一个关于当时的故事
和当下发生在我周围的事件在我的脑海里从个人观点来看的历史。超材料领域有非常非常
多的子领域; 我不认为任何人有能力完整描述这个现在包含成千上万的研究人员的贡献发
展的一个完整历史。
But, for me, the beginnings of metamaterials were very modest. I had no grand
visions, or particular end goals. Metamaterials, or artificial materials,
were for me just a hobby, really - a means of trying to understand an
entirely unrelated phenomenon. I never anticipated that negative index
materials, or cloaking, or any of the other almost magical properties of
metamaterials would exist. All of the really big discoveries made in this \
field, by our group or by other groups, were all pleasant surprises!
I don't know how a discovery is "typically" made. What I find interesting
about the events that led to the development of the metamaterials field is
the seeming randomness of events and, maybe, the luck that was involved. If
there is any message here, it is to learn as much as you can about everything,
as deeply as possible; and, to play around with ideas until you obtain an
almost intuitive knowledge of them. As you build an internal mental
picture of a subject, you also want to allow that picture to evolve and adapt
as you gain more information. Being intellectually honest is also important -
never let your desired outcome interfere with reality, however tempting! I
suspect these very generic and simple rules are prerequisites for progress
and discovery in any field, but I can only give a firsthand account of what
happened for the case of metamaterials. By definition, a discovery is
something you don't anticipate, so all you can do to make a discovery is be
very aware; be opportunistic; and gain as much knowledge as possible.
但是对我而言，超材料的开端是非常普通的。我没有宏大的愿景或特定的终极目标。超材
料或人工材料在以前对我来说真的只是一种嗜好， - 试图了解一个完全不相关的现象的
一种手段。我从来没有预料负折射率材料，或隐形斗篷，或其他以另一近乎神奇的特性的
超材料会存在。我们的研究团队或其他的研究团队都惊喜于超材料所有在这一领域取得了
非常大的发现，！
我不知道超材料的发现是如何“典型地”进行。我觉得有趣的是有关导致该领域的发展的
事件的发生看似随机地发展，也许这牵涉到运气。在这里如果有相关的任何讯息透露是:
尽可能地广泛并尽可能地深入地学习你所了解的一切; 并且一直”玩弄”的物理想法，直
到你认为是理所当然的直觉。并在你的脑海打造一个以此领域为主题的物理图像，如果你
想更进一步地让那个物理图像进化和适应在脑海里让你获得更多的信息。理智上地诚实也
很重要 – 然而绝不要让你所渴望的诱人结果来干扰实验事实！我怀疑这些非常通用的且
简单的规则是任何领域进步和发现的先决条件，但我只能给当时对超材料所发生的情况做
为第一手资料。根据定义，所谓的 发现 是一些你不预期的事，因此你对所发现能做的是
尽可能地清楚地了解;带点碰运气的;并尽可能地获得知识。
In the following, I provide my personal background and perspective on the
events surrounding metamaterials, but I also try to include conversations and
discussions and arguments I had with my friends and colleagues. People assess
and react to the unknown very differently and with very different states of
mind. I think, for the case of metamaterials, the controversy that erupted
and the back-and-forth scientific discussions really highlight the excitement
that resulted as our collective intuition was challenged by some of the
notions that emerged. It was great to be at the center of the metamaterials
explosion; metamaterials continues to be an endlessly fascinating field with
seemingly endless possibilities. Although some of the arguments and debates
were frustrating at the time, I never blamed anyone for expressing an
alternative point-of-view; I have come away from the entire experience with
the belief that the scientific community as a collective is dedicated,
sincere and robust. I'm always amazed at the willingness that others have to
deeply evaluate and investigate any idea that arises, for no reason other
than pure scientific curiosity. It's a healthy impulse that guides us all to
the truth and makes possible the intense progress that benefits all of our
lives!
接下来，我将对关于超材料周围的事件提供个人背景和的个人观点，但我也尝试包括与我
与我的朋友和同事们的对话和讨论及争论这个话题。对于这个未知领域的人反应和接触都
非常不同，并且反应出非常不同的心理状态。我认为，超材料的所爆发的争议和背后反复
不断地科学讨论，导致违反我们当下集体的直觉被挑战，正是这些新概念的产生真正地突
显这种兴奋。这在当初超材料领域爆发时刻是非常伟大的;超材料看似无限的可能性至今
仍是无止尽迷人的领域。虽然当时有些论点和辩论当下曾是令人沮丧的，我在表达个人观
点时从来没有指责任何人; 我在科学界的经验一路走来一直是: 敬业、真诚和稳健的体验
。我总是惊讶于有非常深入地探讨和思索任何新的点子想法的人出现时，这正完全是人类
出自于纯科学的好奇心的意愿。这种健康的鼓励引导我们迈向所有的真理且尽可能快速的
进步来利于促进我们的生活！
这世界发现负折射
It was in mid-December of 1999, during the time our manuscript on negative
index materials was under submission to Physical Review Letters. While doing
some background research, Willie Padilla and I had run across a paper by
Russian physicist Victor Veselago, published in 1968, that had theoretically
predicted the existence of the artificial material we had just succeeded in
creating and had demonstrated in the lab - a material with a negative index
of refraction. Because our material was actually a construction of little
copper wires and rings rather than a conventional material, we were calling
it a "metamaterial," a term that had just recently been coined to describe
artificial materials. Shelly Schultz, my PhD and postdoctoral advisor, burst
into my office one day, really excited - practically breathless.
"I've been in this business for over forty years, but now I'm going to do
something I've never done in my life." As often with Shelly, he delivered the
news with a level of seriousness that bordered on the dramatic.
"What's that? I asked.
"I'm going to organize a press conference on the discovery of negative index
metamaterials at the American Physical Society March Meeting in Minneapolis."
当时那是在1999年12月中旬，在我们关于负折射率材料的手稿提交给物理通讯评论
(Physical Review Letters)期间。当时做了一些相关背景研究，Willie Padilla和我偶
然发现了一篇前苏联物理学家Victor Veselago于1968年的论文，他曾从理论上预言了人
工材料的存在，这正是我们刚刚成功地创造并在实验室中证实 - 一个折射率为负的材料
。因为我们的材料实际上是一些小铜线和铜环所构成，而不是一般的传统材料，我们称此
为“超材料”，即最近刚刚被用来形容人工材料的术语。有一天，我的博士和博士后导师
Shelly Schultz真的是很兴奋地；几乎喘不过气来冲进我的办公室-。
“我已经在这个行业超过四十年，但现在我将会做一些从来没有在生命中完成的壮举。”
由于经常伴随着Shelly发表的新闻是以某一种看似严重程度但是近乎戏剧性的发展。
“那是什么？我问。
“我将筹办明年美国物理学会三月会议的新闻发布会，地点在Minneapolis筹办有关负折
射材料的发现。”
While initially skeptical about the artificial material work, over time
Shelly had become truly inspired, especially once we had discovered the
Veselago paper; now he was brimming with enthusiasm. Shelly held a deep and
profound passion for science and especially loved to challenge himself and
others with intellectual puzzles and conundrums. This passion made him a
dynamic and dazzling lecturer who could inspire and transfix his audience, as
he rattled out physics concepts with a rapid-fire, machine gun like tempo.
Though most of his life had been spent in San Diego, Shelly had never lost
the fast-paced, New York delivery that he was well known for. Shelly didn't
just present the facts; he liked to build a story, usually dangling some
mystery in front of the audience at the beginning of a lecture, then building
up to the resolution for a grand finale. His lectures were thus engaging,
delivered in an inimitable style that left his listeners excited and wanting
more. He was one of the very few professors at UCSD who routinely had a 100%
approval rating from his classes - a nearly impossible feat.
尽管一开始怀疑的人工材料的工作，随着时间的推移，Shelly已经变成真正的振奋人心，
尤其是当我们发现了Veselago的论文； 现在他洋溢着热情。Shelly保持着对科学的深刻
和深远的热情，尤其是他自己喜爱和他人挑战智力上的困惑和难题。这种激情使他成为充
满活力和光彩夺目并鼓舞和让他的听众目瞪口呆的讲师，因为他以机关枪一样的节奏急速
地慌乱了物理学的概念，。虽然大多数他的生活已经过了在圣地牙哥(San Diego)，
Shelly从未输过的快节奏，纽约的发行，他是众所周知的。Shelly不只是呈现事实; 他喜
欢搭建了一个故事，通常是在演讲的开始在观众面前晃来晃去增添一些神秘感，然后建立
解决问题为压轴。他的演讲都是这样如此迷人的，在一个独特的风格，留给他的听众激动
和欲罢不能。他是极少数教授在加州大学圣地亚哥分校(UCSD)的课经常有100%的出席率，
一个几乎不可能完成的壮举 –
In Veselago's paper about negative index materials, Shelly had found one of
the greatest mysteries that he had ever come across. His intuition had been
knocked for a loop, and Shelly was reveling in the endless puzzles that a
negative index-of-refraction brought. Veselago suggested that nearly all of
electromagnetics would have to be rethought if negative index materials were
ever found and we had found them! Everything that Shelly had taught for forty
years - even basic concepts, such as Snell's law of refraction - now required
a second look. For Shelly, this was big news, and he wanted to share it with
the world.
在Veselago关于负折射率材料的论文，Shelly发现他曾所未见所遇到的最大的谜团
之一。当时他的直觉大吃一惊，Shelly陶醉在负折射率所带来无止尽的难题的思想。
Veselago建议:如果负折射率材料被发现，则迄今发现的几乎所有的电磁学都必须重新
思考，而我们已经找到了他们！甚至基本的概念，例如折射的Snell折射定律 - - 这
Shelly曾教了四十年的一切现在需要第二次看。对于Shelly而言，这是个大新闻并且想
要与世界其他人分享。
I, on the other hand, was shocked and almost immediately paralyzed with fear.
Why did we need a press conference? A press conference would mostly target
non-scientists; why would the general public be the least bit interested in
something as arcane as negative index? What immediately jumped into my mind
was all the press that had been generated by the cold fusion experiments
years before, in which a group of scientists from the University of Utah had
claimed to have accomplished a nuclear fusion process in a material. The
images of the Utah scientists prematurely celebrating their presumed
breakthrough with Champaign suddenly came to mind. Similar to what Shelly was
proposing, the Utah group had decided to announce their results before their
paper was published, before the rest of the scientific community even had a
chance to confirm their findings. In the end, when the results could not be
reproduced, the Utah scientists - perhaps unfairly - suffered enormously.
另一方面，我非常震惊并且几乎陷入立刻瘫痪的恐惧。为什么我们需要一个新闻记者
会？新闻记者会将主要针对非科学家; 为什么一般大众会对一点点神秘感的负折射忏生兴
趣？立刻跃上我的大脑里产生的全是由当年新闻界说已经由冷融合实验那几年，其中一组
来自犹他大学(University of Utah)的科学家曾声称在材料中实现核融合的过程。犹他大
学的科学家用香槟过早地庆祝他们假设的突破的影像突然浮现在脑海中。类似于Shelly被
建议，在犹他团队决定宣布他们的成果的论文发表之前，在这之前科学界的其他人，甚至
有机会以确认他们的发现。最后，当实验结果不能被重制，犹他大学的科学家 - 也许遭受
巨大的不公平 。
A press conference could seriously backfire. We had done a very interesting
experiment, for sure, but we had no idea if negative index was actually
useful for anything; moreover, all of our interpretations had not been really
tested. We were drawing our conclusions by inferring a lot from a combination
of experiments and simulations; there would need to be much more work done to
really substantiate the results.
But Shelly was adamant. He saw negative index as an important breakthrough
and was convinced the rest of the world would be as fascinated as he was.
Brushing aside my concerns, he wanted to organize a press conference, and he
wanted me to go with him to Minneapolis to participate. My only consolation
was that, unlike cold fusion, which stood to solve the world’s energy needs,
no one would understand or care about negative index. If we were somehow
wrong or had misinterpreted our results, maybe we could still go unnoticed.
记者招待会可能会严重适得其反(事与愿违?)。我们已经确定做了一个非常有趣的
实验，但是我们不知道，如果负折射率是用于什么实际的用途；此外，我们所有的解释并
没有得到真正的检验。我们的结论透过一连串实验和模拟组合的图表推断; 将有需要做
更多的工作证实实验结果。
但Shelly态度十分坚决。他认为负折射率作为一个重要的突破，并深信世界的其他人
将和他一样为之着迷。撇开我的顾虑，他想组织一个记者招待会，他要我跟他一起去
Minneapolis参加这会议。我唯一安慰的是，不像冷核融合坚持解决世界的能源需求，没
有人会了解或关心负折射。如果我们以某种方式错误或错误诠释了实验的结果，也许我们
仍然可以被忽视。
As the time of the APS meeting and press conference drew near, reporters
started calling. And calling. And calling. I had thought no one would be
interested, but it seemed like everyone was interested.
"I was on the phone for more than an hour with the science reporter from the
New York Times, Shelly announced one day ."I tried to explain negative
refraction to the reporter, but I'm a little disappointed that he had so much
trouble getting it. Shelly seemed genuinely surprised.
The New York Times? Seriously? That was coverage I hadn't expected in my
wildest thoughts. And many other major newspapers were also calling and
considering running the story. There wasn't much I could do. I could only
answer questions if any reporters or journalists decided to call, to the best
of my ability. The cat was out of the bag, and there was no turning back.
随着APS会议和记者招待会的时间逼近，记者开始不断地打电话。打电话。打电话。我
原以为没有人会感兴趣，但它似乎像大家很感兴趣。有一天Shelly宣布
“我在电话上和超过与来自纽约时报的科学记者通话一个多小时。”
我试图向记者解释负折射，但我有点失望他有很大的麻烦理解它。Shelly似乎真的感到
很惊讶。纽约时报？认真的吗？我从没想到那是直播这是我最疯狂的想法。和许多其他主
要报纸也打电话，并考虑讲这件事。所有我所能做的只是，如果有任何记者决定打电话给
我，尽我最大的努力能回答问题。猫已在袋子外面，而且没有回头路了。
For the press conference, the staff at APS wanted a couple of distinguished
physicists to be on a panel to support and discuss the results. Shelly asked
Walter Kohn, a physicist at UC Santa Barbara who had won the Nobel Prize in
Chemistry in 1998, and Marvin Cohen from UC Berkeley. They were both
intrigued with the negative index after Shelly explained to them the
experiments, and graciously agreed to be on the panel.
The press conference was held in March of 2000, about a month before the
paper would be published in early May. While reporters and possibly some
researchers would have copies of our manuscript to evaluate, most other
scientists would not. I was incredibly uncomfortable with it all! The night
before the press conference, I couldn’t sleep, distraught and almost sick
with the thought that we were making a big deal about our work when we might
have missed something technical, or were overstating the significance. It was
frightening.
在记者招待会上，美国物理学会(APS)工作人员在面板上想了一对杰出的物理学家来
支持和讨论的结果。Shelly问一个在加州大学圣巴巴拉分校赢得了1998年诺贝尔化学奖于
的物理学家Walter Kohn与加州大学伯克利分校Marvin Cohen。在Shelly向他们解释了实
验结果之后，他们都对负折射率感兴趣，并慷慨地同意成为在面板上的人物。
2000年3月召开的记者招待会上，五月初大约论文即将发表一个月的之前。尽管记者
还有一些研究人员可能将有我们的手稿的影印本来评价，虽然大部分其他科学家不会。我
是极为不舒服这一切的！当晚的记者招待会前一晚，我几乎睡不着而心烦意乱，对我们正
在做的工作做了极大的思考几乎快生病。我们可能已经错过了一些技术性的，或者工作被
严重夸大重要性。这是令人恐惧的。
The concept of a negative index of refraction is pretty technical. Shelly had
a talent for explaining complex ideas and making people feel like they
understood them. He was at a stage in his career where he knew how to convey
the big picture, and not get bogged down in the technical details. I didn't
have that talent. Moreover, Shelly was not shy; he was outgoing and filled
with self-confidence. I was far more the introvert, and also riddled with
doubts that we hadn’t been self-critical enough with respect to our theory
or experiments. I was terrified about every statement I made, and tried to
qualify every sentence to the point that everything I said became useless. As
I anticipated the day of the press conference, I imagined trying to explain
negative index to journalists, or - even worse - trying to answer what
negative index might be good for. The thought of telling a reporter "negative
index is good for reversing Cerenkov radiation" made me queasy. Even trying
to explain what a "magnetic permeability" and an "electric permittivity,"
which were absolutely necessary to understand the structure we had build, was
next to impossible. Those concepts are difficult enough for physicists to get
straight!
负折射率的概念是相当地技术性。Shelly有一种天赋解释这复杂的概念，使得人们觉
得自己了解它。他是在他的职业生涯一个阶段，他知道如何传达大局，而不是为了得到的
技术细节越陷越深。我没有那个天赋。此外，Shelly不是腼腆; 他是非常外向并充满了自
信。
我十分内向也充满了疑惑，我们对于我们的理论或实验没有足够的自我批判。我很担
心我的每一个声明并试图资格使每一句话到如此的地步:我说的一切变得毫无意义。正如
我在记者招待会当天预期，我想像试图解释负折射率给记者们，或者 - 甚至更糟 - 试图
回答负折射率可能是可能是有益的。告诉记者“负指数有利于反转Cerenkov辐射”让我作
恶。甚至还要努力解释什么是“磁导率”和“介电常数”，这是对我们所建立的结构所绝
对必要的了解对记者而言几乎是不可能的。这些概念即使对物理学家都很难直接了当的理
解！
Shelly's enthusiasm, though, was unbridled and unstoppable. "Negative index
is a major, major discovery!" He'd say, "What is it good for? I don't know.
But when the laser was invented, no one knew what to do with that either, and
now lasers are in supermarkets. No one could have predicted that!"
Negative index was pretty neat, but, in the end, we were scattering
microwaves off of metal. To my mind, while we had found a really interesting
effect and fulfilled a thirty year old conjecture, it wasn't the same as
demonstrating a laser, which had produced non-classical, coherent light for
the first time based on a quantum mechanical effect. I would never have
compared our metamaterial structure to the laser.
But, despite all of my reservations and concerns, the press conference went
forward. And, instead of no one being interested, the science journalists
were really intrigued and negative index looked like it would become the
story for the 2000 APS Meeting.
Shelly的热情，虽然是不受拘束的和不可阻挡的。
“负折射率是主要的重大的发现！”
他会说，“这是什么好处？我不知道，但是当雷射被发明出来，没有人知道该怎么做，现
在雷射是在超市可买到，没有人能够预料到！”负折射是相当巧妙的，但是，最终我们被
侷限在金属中散射微波。在我看来，虽然我们发现了一个非常有趣的效果，并实现了三十
年前的猜想，这是不一样的展示雷射，它已经产生基于量子力学效应的第一次非经典的同
调光。我从不会比较超材料结构跟雷射的不同。但是，尽管我所有的保留和关注，记者招
待会上前。并且，没有一个不是不感兴趣的，科学记者们真的很好奇负折射且看起来像它
会成为2000年的APS会议的故事。
As I had expected, it was a difficult topic for the reporters to cover, and
equally difficult to convey the importance. I also had my first experience of
dealing with science reporters, which turned out to be fantastic. The
journalists who covered the science stories truly loved science and tried
very hard to get the story right, while making it palatable for their
audience. I was deeply impressed with their care in writing the story, fact
checking and allowing us to review drafts for accuracy. They worked hard
trying to explain our own discovery for us, suggesting analogies and even
postulating possible uses for our arcane materials.
正如我所料，对记者报导这个主题是困难的，并同样地难以传达的重要性。我也第一
次和记者相处的经验原来是奇妙的。报导这些科学故事的记者真正热爱科学并且很努力地
让这个故事的正确性真实呈现，同时也使他们的观众愉快地接受。我在写故事让因为他们
的关心被深深地打动了，核对事实并让我们回顾草稿的准确性。他们努力试图解释我们的
发现，建议类比甚至为我们的神秘物质可能的用途的提出假设。
I also got a sense of where accuracy has to be sacrificed for the sake of
generating interest or conveying to non-specialists quickly. At one point I
was working with a reporter from the Washington Post, who was covering the
APS press conference. He was on the phone with his editor, and we were making
last minute changes to his story just before his deadline. The editor wanted
a title.
The reporter was listening to something the editor was saying. Then, he
cupped his hand over the phone and leaned over to me: "My editor likes the
title 'Left-Handed Material Said to Reverse Energy.' Is that ok?
I thought about it. "No, our material really doesn't reverse energy-I'm not
even sure what that means exactly. Our material just scatters waves, and
inside the material waves appear to propagate the wrong way, back toward the
source. But it's just an illusion; the flow of energy is still the same. The
title is definitely misleading, if not entirely wrong."
The reporter got back on the phone to the editor. "He says your title isn't
right. Energy doesn't go backwards. Yeah. Yeah. Ok."
我也感受到了为了让非专业人员产生兴趣或快速地传达给非专业人员讯息，牺牲精确
度是必须的。有一次，当我正与华盛顿邮报记者工作时，他在播报美国物理学会(APS)的
新闻记者招待会。他与他的编辑在电话中通话，且我们只是他的最后期限之前做出了最后
一分钟改变他的故事。该编辑想要一个标题。
记者在采访中听到一些编辑在说什么。然后，他用他的手遮著电话并俯著身对我说：
“我的编辑喜欢这标题”左手材料说成反转能量。“ 这样可以吗？
我想过这个问题。“不，我们的材料并没有真的反转能量 - 我甚至不确定这代表的正确
意思是什么。我们的材料只是散射波，在材料内部的波传播了出现了错误的方式，回到光
源，但它只是一个幻觉，能量的流动仍然是相同的。这标题如果不是完全错误的也绝对是
误导性的 “。
记者回电给编辑。
“他说，你的标题是不正确的。能量没有后退。是啊、是啊，好吧。”
The reporter leaned over again, hand over the phone and declared "we're gonna
run with that title anyway. My editor likes it."
Not much I could do! The article was great, and, wrong as it was, the short,
catchy title would unquestionably attract readers' attention.
To my surprise, the press release from the APS (which can be viewed here) and
the press conference caught fire and within a week everyone was talking about
negative index. The story was global, and reporters even found and obtained
comments from Victor Veselago, who had postulated about negative index more
than three decades before.
记者俯身再次交出手机并且宣布“我们要运行这个标题呢，我的编辑喜欢它。”没有太多
我可以做！这篇文章是伟大的，而且，错了，因为它是中，短，吸引人的标题无疑地会吸
引读者的注意力。出乎我的意料，从APS（它可以被看作新闻稿在这里）所发布的新闻且在
新闻记者招待会起火，在一周之内每个人都在谈论负折射。这个故事是全球性的，记者甚
至发现和获得三十多年前提出负折射假设的Victor Veselago的意见。
开端
In 1997, I was into my third year of a postdoc in the group of Sheldon
("Shelly") Schultz, in the Physics Department of the University of
California, San Diego (UCSD). I had completed my PhD in the same group in
1994, on the topic of microwave scattering in photonic crystals. After
graduating and becoming a postdoc, I had switched research topics, and was
now investigating the optical microscopy of metal nanoparticles. While the
two topics may seem unrelated, they both involved the interaction of light
with materials - structured materials, in the former case; and metals, in the
latter. My postdoc advisor, Shelly, had formed a company called Seashell
Technologies to try and commercialize the metal nanoparticles for use as
super bright labels in biological assays. As part of my postdoc research, I
was to develop methods to simulate and better understand how light interacted
with the metal nanoparticles and how we might optimize them.
Why metal nanoparticles?
1997年，我在加州大学圣地亚哥分校（UCSD）的物理系的 Sheldon ("Shelly")
Schultz教授的团队底下当第三年的博士后。我在1994年同一团队已经完成了博士学位，
当时念博士时在研究在光子晶体微波散射的题目。博士毕业并成为博士后之后，我又转而
研究课题，当时正在研究金属纳米粒子的光学显微镜。尽管这两个题目看似无关，它们都
牵涉到光与材料的互相作用 -在前者(博士时)是以光与结构材料交互作用; ，在后者
(博后时)是光与金属交互作用。我的博士后导师Shelly曾成立了一家叫做背壳(Seashell)
的公司尝试技术和商业化的金属纳米粒子作为生物测定的超亮标签。由于我的博士后研究
的一部分，我是发展模拟并更佳了解光与金属纳米粒子如何相互作用的方法，并且如何对
其进行最佳化。
为什么金属纳米粒子？
As it turns out, certain metals scatter visible light like crazy. The
incident electric fields of the light cause the electrons in the metal to
oscillate, scattering the light with enormous efficiency. If you look at a
bunch of silver nanoparticles under the right kind of microscope, they look
like bright, colorful beacons, or colorful stars in the night sky. Physicists
have longer understood the basics of why the metal nanoparticles are so
bright: Light impinging on a metal sphere, for example, is a classical
physics problem that can be solved exactly; all that is needed to describe
the problem is a certain property of the metal called the "electric
permittivity,"" which is denoted by the symbol . No matter how complicated
are the microscopic details of a material, its response to electromagnetic
waves (like light or radio waves) can be mostly understood by just two
parameters: The electric permittivity, ε, and the magnetic permeability, μ.
For most non-magnetic materials, like metals, you can ignore μ entirely, and
pretty much describe all the optical properties of the material just by ε.
For certain metals at optical wavelengths, ε is a negative number. A
nanoparticle that has a negative ε can actually bind light on its surface,
squeezing the light into nanosized regions that are much smaller than the
wavelength of light. This tight, localization of light is one of the main
features of metal nanoparticles and what makes them so fascinating to study.
It also makes them really tough to study.
事实证明，某些金属的散射在可见光像发疯似的。光的入射电场导致在金属中的作振
荡，散射光具有巨大的增益。如果你在合适的显微镜看一束银纳米粒子，它们看起来像明
亮的，多采多姿的烽火，或是在夜空中丰富多彩的星星。物理学家们很久以前就已经知道
为什么金属纳米粒子是如此明亮的基本知识：比如，光照射在一个金属球是可以有精确解
的一个经典物理学问题; 所有这一切需要说明的问题是所谓的“电容率”，“这是符号记
为 的金属某些性质。不管有多么复杂材料的微观细节，其对应于电磁波（光或无线电波）
就只要了解这二个参数，介电常数 和磁导系数 。对于大多数的非磁性物料，如金属，
可以完全忽略，和许多几乎所有描述材料的光学性质一样，我们关注主要是 的性质。
对于某些金属在光波波长， 是一个负数。具有负 的纳米颗粒实际上可以结合在其表面上
的光，挤压光波进入纳米尺度，这是比可见光的波长小很多。这种紧密的，局域化的光是
金属纳米粒子的主要特征之一，这是为什么他们让人如此着迷的研究。
这也使得他们真的很难学。
Because light can vary at a scale much smaller than the wavelength on a metal
nanoparticle, it is hard to compute light scattering from a metal
nanoparticle that has an arbitrary shape. Most electromagnetic simulators
solve for the electric and magnetic fields at a discrete number of points
within a volume. Normally, the density of points needed is a few times
smaller than the wavelength. For metal nanoparticles, though, a much larger
density is required, meaning way more points to capture the physics
accurately. And so, the computational time shoots up as does the required
memory. While the computational difficulties are much more tractable now, the
"plasmon" problem was a major challenge in 1997!
Since our group was more on the experimental and conceptual side, it didn't
seem like developing and debugging numerical methods was the most efficient
task for me. Luckily, at a near-field conference I attended in the Czech
Republic, I saw an inspiring talk by Olivier Martin (then a postdoc at the
ETH in Zurich), who presented what looked like the ideal method for computing
the properties of nanoparticles. His was the first talk of the conference,
and I knew immediately that his method was the one we should be using! At the
conference I was able to discuss the plasmon problem with Olivier, and he
also became very intrigued with the challenge. He was very happy to visit our
group in San Diego and help us get a more quantitative understanding of
nanoparticles with different shapes. His method was great, and we
collaborated closely for many years.
Still, it was a struggle to figure out exactly what was going on with these
nanoparticles, especially when trying to match up the simulation predictions
with what we were seeing under the microscope.
因为光可以在尺度上变化上比金属纳米粒子的波长小很多，所以具有任意形状的金属
纳米颗粒计算的散射光的计算是非常困难的。大多数电磁模拟软件解决的电场和磁场在一
个离散点的数目的体积内。通常情况下，所需的点的密度是小于波长几个数量级。然而，
对于金属纳米颗粒，更大的密度是必需的，这意味着需要更多的点来精确地获得其物理性
质。
因此，计算时间拍摄所需要更多的内存。目前计算的困难听话是服从的多，
“电浆(等离子体)”的问题是在1997年是主要的一大挑战！
由于我们团队为更多的实验和概念方面，对我来说最重要的是最有效率数值方法不像
是开发和除错的数值方法并太重要。幸运的是，在我参加的一场捷克共和国近场学术会议
上，我看到了一个鼓舞人心的讲座，由Olivier Martin（当时他是苏黎世ETH的博士后）
提出看起来像计算纳米粒子的性质的理想方法。他是会议的第一个讲者，我马上就知道他
的方法正是我们所需要那一个！在这次会议上，我能够和Olivier讨论这个电浆问题，而
他也对这问题充满非常好奇与挑战性。他很高兴来参观我们在圣地牙哥团队，帮助我们获
得具有不同形状的纳米粒子更定量的了解。他的方法是伟大的，我们密切地合作多年。
不过，试图在模拟预测与我们在显微镜下所看到的结果弄清楚这些奈米粒子到底发生
了什么事情，这是一场挑战。
(待续)
PS:欢迎帮我当初自己翻译文章修饰得更好,当时我只是为了了解一些物理和历史