OK I sent you very much for the introduction Good afternoon everyone First I'd like to stand up Professor for inviting you to speak here today I'm going to discuss our recent research about materials in both the lunar and on learning the reteam so I'm not sure if everyone in this audience are familiar with the basic concept of metamaterials So I think in the first like a twenty percent of my talk I'm going to focus on the very basic concept of metamaterials in the conventional linear retrieve him including some of my result of train the quite some time of Goldman five or six years ago and their authors that I'm going to move on to more advanced topics or not in the control and the interactions in optical metamaterials. So. Discourse in the media for metamaterials let's first try to clarify what is our material of course everything in the material so let's discuss what is the material within the concept the the framework of electro mathematics so every scene in a homogeneous as long as you look at it closely enough and the way we describe the electromagnetic a property of a structure is a critically dependent on just to give you. Compared to the wavelength and the cause of the region we look very very large. We use just the retreating and the dramatic optics system like an optical microscope or telescope if the dust of your home would be near it he is comparable to the wavelength and the consideration in this case the electromagnetic The properties are largely covered boy diffraction and interference phenomena within this category include for example the actual rate of reaction increased host the photon you create. The. A reform in the soul so structure can be safely referred to cure as an electromagnetic material only when the Secu of a. In the march the morning that we have less and the consideration in this case we can use the Maxwells you creation along with the whole denies the much Europe including electrical primitivity magnetic permeability new refractive index. Impedance the and the so on to describe its electromagnetic property so measurement you're a force within this reach him very much similar to conventional Christo metamaterials consist of artificially structured so what matter at homes and the molecules with their side and the separation much smaller than the wavelength and a consideration. So. The reason why we started off the whole mess of materials is basically because the optical properties of a W. natural occurring materials we present only a very limited subset of what are available in nature if we based on this two important parent Hearst. And the mule we can trust to classify all the electromagnetic materials. Used in this so called The paramita space at offical frequencies we have so many different materials including semiconductors transparent crystals gaseous metals but is there optical properties all limited with extremely narrow zone along this line knew it costs you one so the go for metamaterials search is to expand this paramita space to produce something that are not forbidden by Max or see creation but not read a little bit of the nature. So let's first start with a very simple one electrical metamaterials which means artificially structured metal composition with a prescribed electrical property your rate is. A function of what is our value this is actually not a new idea since a many years ago fifty or sixty years ago the microwave engineers started to use the term artificial Pal actually. To describe things like this one OK metallic structure is a periodic Lee. Your host no matter who you are Bash is a very good example for the so-called artificial trick. Similar to your so then that the metal the electromagnetic the property of such as the incumbent is the model but in this case the Juda paramita us are related and can be proportionally tuned by the dramatic apparent herself these were a mesh. Mathematical Metamath you receive the much more attention then the electrical current part is special at the optical frequencies because we always want to create something new something that are not available in the church so in this talk I'm not going to really just a glass Why is no natural occurring you magnetic response at optical frequencies but almost everyone takes this for granted we can see if we don't really worry about the paramecium you we only use the actual cost and or permittivity. More often than not we use the root of. The refractive index. If you look at some standard textbook Landau's the E.C.M. A forgive them Paul you have find such explicit statement there's certainly no meaning in using mathematical susceptibility from optical frequencies on board and in this article for such phenomena we must put me to one. This scenario has changed dramatically in the past to roughly fifteen years ten to fifteen years. The Supreme through resonators proposed by Sir Paul Pendry roughly fifty years ago is probably the most important. For Megadeth metamaterials and there are certain conditions this couple the readings and the cap still has an L.C. circuit so that magnetic moment then the circular current can be excited by the magnetic a few of the components of the electromagnetic wave. The so-called S. all simply really resonate here were first that demonstrated at the microwave frequency. And after that a smaller rooms and those are the realities has been demonstrated to push the high frequency limit of artificial magnetic response all the way up to the near infrared. However such a structure is not going to provide any noticeable magnetic response. Because there's a for demand whole specialisation effect in the high frequency limiter which is related to the finite election tensity in the metal so we have to find new structures. So. We realized the controllable magnetic response across the entire visible spectrum use the a structure so called A couple the normal stripe structure basically a how a real financial stripes this you need has a two stripe separated about their space or so and are certain condition magnetic response can be insight either by the magnetic field component of light. This figure figure shows the spectral behavior for a typical whole. With the simple reason of I believe roughly one hundred twenty one hundred thirteen enemy and the from this spectrum you'll see there's a number of important features for the so called a key am not polarization with the magnetic a few of the price along the threads so the feature you can see is diffraction feature electrical and the more importantly a magnetic resonance at the mathematical resonance of wavelengths or frequency you'll see within this metallic stripes the circular current displacement current can be excited by the magnet of the feud component of the light which give rise to artificially. Induced a magnetic response in the structure. So what you are looking at here or microscopic imager is and literally the light for both of the transmission and the reflection spectrum basically we fabricated a serious of the. Structure where the drape. This is a very that you locate a resonance condition for different frequencies you see that for the rest of the T M A motor with a magnetic a few with a polarized along the stripes you see different colors in both the transmission and reflection mode indicating various resonance conditions but of course NY resonance A to see your mode with the electrical fuel the price the along the stripes actually this structure serves no more then. The metal. With a more reflection and the last transmission for longer wavelengths that is the wife or the non-rational the T.-E. motor or the stem hose appear to be blue for transmission mode and the dreaded for the reflection mode. So here you see resonance imagine that we have a lens as a function of a supply previous So basically if you change the script from one hundred thirteen and a meter down to fifteen nanometer you have cover or you can create a magnetic response covering almost the entire spectrum from seven hundred fifty nanometers down to four hundred sixty nanometer and this curve is pretty linear which means that it's really a. Factor as a for the effective apparently. Or mathematical reality from the structure it can be anywhere minus two and the processor upon foil but all substantially away from the number you have to lie of course or one that you always have in naturally occurring materials. So now that we have the magnetic response and the control we want you just move one step further to create create something more extraordinary that is a material without a negative refractive index or the negative interaction material pretty much a new research field or probably it's not a very surprising to learn that a few scientific gents actually consider this phenomena long before the recent to matter much your research. So the never to group and then to face we lost the key was proposed the buy shoes for the lamb more than. One hundred years ago any more details in nine hundred forty is. The first a systematic study of a metamaterials including the negative index of materials was actually beauty the tube the larger nine hundred sixty S. and the since fifteen years ago Pendry was the one who initiated the research field of. Mature and the metamaterials. So Maxwell So you question to find the reflective in there as the root of the meal and as a first pointed out by Vista lurker. And the new Austin one tenuously Nabatean a nephew will sign must be true simply for the six guards. To study the fact his ality. Of course is not just of mathematical trick the sign of a refractive index has a for the mental impact on almost all the phenomena related to the phase of a light if you look at the relation between the three important parent. K. wave after aging Magnetic a few and the he electrical field you'll see that if the reflect mean that if both no and the me you are being nagged if you will then the energy flow is a to react to a lot of the reaction against the face propagation represented by this caveat here consequently if you have a light of entry and that given that some of your from the free space not only is the light being against our common stance with this and that if you mean that the material the face propagation is also directed against the reaction for the energy for the. Previous three we learned that. To do the mathematical metamaterials with another human meal then the. Metamaterials. We are certain we are going to probe why there are negative if so low there in Syria if you put these two system must care there you should be able to realize a now that you refractive index this is exactly the idea between up behind the for us the one due to the or three dimensional given that the materials at the microwave frequencies. On four hundred three the same strategy will not really do anything good at offical frequencies at least I have no idea how to shrink the size of the years a very complicated structure by. Ten thousand times to make the move at optical frequencies so we have to find a better ways so in order to realize the negative index of refraction at optical frequencies for the first time we. Spoke with a cup holder know who wrote the structure and are certain conditions improve quality is such a structure can give rise to our current and the matter that the pipe holds we responded to the magnetic field a component of light the same structure also serve as an electrical process. So if you combine these two in fact the Nazca index of refraction was realized for the first time at offical frequencies so based on the. Experiment only of pain the complex values of the reflection and the transmission coefficient you can retrieve and the cattle the effect index of refraction in such a structure so the result shows that at the telecommunication wavelength of roughly one point five zero multimeter the effective index of refraction in the structure is roughly my nurse on the street. The first one negative in X. not sure is not a really high quality one because of the very limited the magnitude of this and that to a value or a long way is a pretty large loss factor Nevertheless this experiment confirmed the existence of negative index of refraction at optical frequency. Pervasive mainstream design for next year index of materials at optical frequencies is so called The fission that the structure previously we are in the OK if the coupled and then last one of us has served as a good mathematical metamaterials and for the same structure if you rotate it by ninety degree you are going to produce electrical plus more what allude to the metal with a negative so if you can why these two systems to gather you are going to have with us then there are so called efficient at the structure as a major for the. Shown in the background based on the fission that the structure people have demonstrated. In that I believe what the yellow light frequency along ways that they react observation of the inverse the Snelson or at the infrared This is. So now let's move on. A different topic in metamaterials the so-called of the Cairo optical metamaterials Carolla to describe the Drug Turf. Mirror image cannot be super imposed onto itself. For example our hands are Cairo this is the left hand which is different from our right hand as a left hander not only because it's connected to my left arm if you cut it off it is to our left hand the right so it's a fundamentally different from our right hand. And the many organic molecules are chiral So this make Carolla here very powerful to the last to use in industry and also in chemical engineering to identify compound and American countries. The direct consequence of your Corolla here include the two things the wind the so-called the circular terrorism which means the only prize the light of the the heaven is that we experience a different amount of. Material and another related the phenomena is called the OP. Rotation or optical activity which means that if the important light is a little me price lighter than the outgoing light of view. By an angle of course the phenomena in these two movies are over exaggerated because the national crane materials actually these phenomena at the very very weak the magnitude of this rotation for example is on the order of merely degree level. We have utilized extraordinarily. Of cocoa response in the so-called the. Metamaterials So the structure that basically you need to look like this one you have to know arcs for shift either by angle and also shifted along the propagation direction of the light wave and then this structure you're into at the differently to the circular privations of operate Hendry's Actually it's pretty straightforward to think of this structure if I ask you what is the past of Cairo structure probably feels a hilly cost structure might be the best the structure just look at the structure of the light field itself or circle Priceline you have the heel of course structure and this structure represented just. One pitch of a hill across structure a SAW it will give rise to a very strong response. So from the numerical simulation you'll see that OK the residence of behavior is a sense here with you the. Direction of the circle in the price of light or L.C.P. and also resonance at different locations this gives rise to a very large contrast between the transmission. Spectrum of which this contrast to your recorder. And experimentally we observe the transmission contrast as a lot is there under three at a resonance and also if you look at the rotation angle for literally price of light the retreat angle can be as large as a fifty degree. These are very Those are very large compared to many orders of magnitude a lot of than what you how we naturally occurring in materials especially considering now we have a test of metal material. The lab will be the second itself less then one hour or five off of the lambda. So just more pictures to play with OK We also see down the structure to make the kind of metal material working at the visible for the visible light so actually it's more involved than now we created so called that to all the data and not and A and then to appear they are mirror image of each was or so of course the optical behavior will be complementary to each other at the you'll see over here transmission curve of the four and a and I also P N R.C.P. and that for P one and that we create a pattern for our mascot so for the yellow jacket I don't know why there was a difference between yellow jacket and a B. or it's different it's the same as A was upright and away so basically we have the two and the tumors that you are two are the attacker mask or the yellow jacket you see that it actually can hardly see any seeing and the Lindley price lighter or light or starlight because you have equal amount of L.C.P. on the R.C.P. for ceiling light or for the sunlight but you can clearly see the image and the circle in the prize the light and the poetry of the image are ever directly related to the hand the nearest of the still clear privation and also relate to the hue the wavelength at which you hit one of these two rashness. So now let's move on to the not only in their matter much you're also a more advanced topic so without a general question of the non in the optics lets first you a few examples of convincing you that there are many interesting behavior that occurs in the morning there are too many of metamaterials again what we are looking at. Here is the so-called official national structure and the worst when properly designed this structure can give rise to a negative refractive index of a certain way of lesser injury for such a structure that you see from the S.C.M. emitter that the. Index to bend occurs at roughly one hundred and then we turn one hundred ten and a meter. So here basically what we are looking at here is the transmitter and the reflection curve. From experiment in the same a figure we also plotted the excitation second how Morning excitation Sabbat term for this fictional structure excitation spectrum means that you fix the intensity of the pump lighter you vary the way of an answer and try to see how much a second I want you can really you get from at a different wavelength so from the in the spectrum you'll see you out there are quite a number of complicating the resonance of behaviorism so you might wonder if we will give rise to the most efficient or second harmonic generation the conclusion is the. Efficiency reaches the maximum possible value or whenever when the refractive index is the most a negative. OK let's look at another example this is a again Cairo metal maturer with this to see the ox OK And we know these two arcs the arcs are real Intacta differently too with the little price light of the head and there is this very large so called a. As a large as a fifty percent and of course this and that A and B. are mirror image of each other so the two curves are complementary to each other. So we created this pattern the thought attack a logo outside of the treaty logo we have an atom or. A right. So it's all because your house. My own still in the sitting in the audience so they can just. Help me with all of the fine details of course so the inside you have and that will be again you'll see that creepy pattern only with a bow and a thoroughly priced Lloyd and the priority of this image is a sense of humor to the. Nation OK and there is a talk. In a white. Background and the R.C.P.T. the bright and talked. And actually the contrast of this image is roughly for one or two OK that he that he reacted relatable to the. Lean into mean so now we can what you are looking at here is the second harmonic image from the same pattern and. So once again you'll see the treaty pattern and the porridge here the related the cue the tenderness of the excitation so fairly priced light but in this case the. Image contrast is a much better then before ten times as a strong as before because here you see a contrast of almost a twenty it's all over the true like this that are the beautiful scene for not in the optics you have a better contrast it's a more sensitive to the rest of the property and therefore So these images are not really perfect because you see a lot of hot spot due to the surface and randomness of the Metallica structure also I don't have a perfect again in. Those data so let's look at the region within the beam OK we prevented a. Circle and there based on this issue as a teenager we can compute the asked. Based on this formula sh or T.C.P. is. It has a where you know that. You minus two and the plus two zero means the no contrast person menace through music infinitely large contrast and the from the as it could be seen major you see indeed metal mature has extremely large as it receives the many orders of magnitude larger than their. Natural Korean counterpart. OK so now I'm going to move on to our another topic because that is a electrically Accu metamaterials for not in objects so basically we know that OK metamaterials or you really moot as artificially structure the materials to be the very exotic of behavior not found in nature actually I want to look at a mental maturity from a entirely different perspective we know that many metamaterials look more like a model as like this you have to pattern the metal fumes separating the by. Using the metals you provided the plaster more response and also and certainly you knew that the actual material separated from the metallic part. And the we know that. Met host of conductors so other than the suit then the rule for the typical metamaterials serve as a plus more Nick metals we also use the thermal metaphor to serve their conventional roles for voltage control for current injection for heat sinking in a saw on the other hand you can use artificial early on or you can use act you the actual materials are likely your polymers for conducting materials junctions to further actuator this material so basically I think metal material can be viewed as not only the artificial destruction of material with exotic optical behavior but rather. Are very general self-contained electromagnetic electro optical platform that has both electrical functions and optical functions. So the first example with this regime is a. Second how many generator based on a single. Cavity we see this in quite a few years ago or not quite of your three years ago so basically if you feel this plus model carried. None in their polymer there's a second harmonic transition from the city of wires can be proposed to me to not apply the voting to signals. So not just a little bit background knowledge about is that no one in the optics and second harmonic generation will step in a harmonic generation also called a frequency it is a typical none in the process and also the condition two photos can be converted into a new four tone with the energy of the initial ones so this is the usually considered as a purely an opcode response of either no electrical functions so what I'm thinking of is that for you it is possible to use the metamaterials as a norm in the medium and then they use a motive stick in order to purposely control the stack to one morning I would put. This so-called the electrical few that were voted to control the second How want a generation is actually not a new idea. So since. More than fifty years ago in night hundred sixty two just a few years after the invention of the first a laser and just one year after the first observation of a second home or a generation. Discovered that second harmonic generation can be observed from a crystal if you apply a strong across the crystal which otherwise shouldn't occur because we know that Crystal has the central symmetry so in Syria to be zero. You see those are really the days of the industrial research either for the motor or was willing to support a basic research like this one which has nothing to do with cross sizing but it's almost unbelievable as these days and the way this electrical field induced the second harmonica is that if. In the from the tender as a tricky because the standard absolutely is not quite your response or make up. For this if it is a syllable Order No one in the response or. Plus plus is zero so this behavior of this phenomena is related to the intensity of the for the man who lied and or more importantly is related to the. D C R electrical field which can be proposed by the voltage signals. So in this world we try to demonstrate that. A metamaterials the metamaterials so called A Perfect. Consist of the periodic a hose your mentality a few months separated by a. Plane or math film with. OK And the last circle wavelength reentry such a structure can suck absorb all the incoming light we see in this space or this configuration give us a few important features that help demonstrate the electrical control the second one can reason because the mathematical structures that support both electrical and optical functions are for the demonstration. And this structure can constantly lie too busy in the padlocked with the base that is immune to the optical intensity and then we know that almost all the running of the Norman are positively related or through the local intensity of the light where you and also you have a nanometers to go actually less than a handle nanometer of. That means that by apply you valuable to a huge level of control water. So. The measurement your absorber is it is liable to have a perfect. At roughly eight hundred twenty nanometer which is the standard of all that the whole range for our of the laser. From the numerical simulation you'll see with their work their luck. The electrical few in the house by six or seven times so that means the intensity is roughly fifty Times Square. And the more importantly within the space are all the field including the light in the electoral field component of the light where you and also the controls the order a coin in the report of a lot of the the reaction that either the reaction. To this is that. This is the preferred configuration because in this case we are we can make you also for the the strongest element in the kite you in the three pence are of the of the a more Force Base which is the Keiser easy OK anyway without too much serious Let's go ahead and look at experimental result so here is the. The image is immediate and as he and a C.M. emitter for first single chip consisting of multiple devices and this is a single to Voice of these are two. Layers connected through two external electrode and within the central part of that is the metal material pattern you'll see there's a pattern OK the fabrication of a metal maturity voice of course is the much more involved then a matter much you're a pattern itself of course it takes a many addition of our steps to make sure that you have to live safely connect to the true external electrode and also the quality of this the more you because you need to make sure that. There's no shots no electrical breakdown and so on. So in the experiment femtosecond laser pulses are part of a set of. Element and all that illuminate the sample the. Second Harmonix the signal is sent. Here the from the for the manhole way with a number of. A few an element and then and her in the P.M.T. for the multiplier or aspect of meter locking in measurement that carried out where the detector signal is locked at you is an optical top her or a function generator. So let's first look at the over or no one in their signal from that the wiser without the appreciation of the voltage so all those subtle structure should have you in principle but actually second harmonics generation and the second order are not in the process it's still possible because you always know how the surface boundaries to mature broken around the surface around the interface between matter and trick basically at each excitation or pump. The outgo you. Know contains a shop peak at a London or a Q. that is the second harmonic generation and a broader Ben. One in the signal which is the cue for the luminescence from the metal metallic structure and the post the second harmonic generation and the two for the luminescence reach their local Maxim are pumped at roughly eight head to the net a meter because of that is the wavelength where the perfect option behavior should occur. The two not in the component for the noise in the second or. Two for the luminescence and second one generation they have a very different spectral behavior and also very different the predation properties from the merriment he will know that OK Second how monitoring the region is predominately along one direction and the two for the luminescence are. Randomly experimentally it's very easy to separate the two component. And the efficiency of the second harmonic generation is a critically related to the leaner behavior of the metal mature absorber so what you are looking at here is the Excite. Patience the Bactrim for second harmonic generation from the device again excitation spectrum you use of. Intensity your very is a powerful wavelength and see how much second harmonic signal you get at each wave list. And though all the same figure we also plotted the linear reflection career over this reflection table means absorption peak that is the wavelength where. Near perfectly absorption would occur you see that the harmonic conversion efficiency reaches the R.. Value as expected at the frequency we are the current that is the linear resonance frequency for the purpose of the other so now we want to fix the way of Lance at this specific away of lens and the youth voters to the nose to the second harmonic generation result if you hear from a post the P.C. and a C. control you see the how much a generation is a linear to the control board for example where you apply across the device and you'll see are not in the modulation taps as a larger temp ascent and the reason for such a linear occur is because actually for the election really induced the second harmonic generations are to both heated relate to the terms and the our case in the last the term permanent so that the why you see this curve and the similar to a standard the second harmonic generation or frequency W. the electrical You control the second home or the generation the signal amount is the related that is critical to the. Intensity of the filament hallway with this also come from an experiment only from our experiment. And. The demonstration of the second election really control the second harmonic generation from a such a device that is just part of the story from the same device architecture we can also demonstrate the voted to induce the end electrically controlled optical Dr. Cation. From this device OK optical rectification if you haven't heard of this term before it's very similar to our second one you can ration as if G.M. is a plus. Or minus on me got a cost to the so the electrically induced optical rectification missed the forty and that is a initially you don't have to and do you the voltage or two because of the interplay of the three Third Order Nonono susceptibility and apply the both heat or you produce electrically induce the OK and then with the externally apply the pump light off or the mental light or a D.C. None in the predation your Kirby's in this space or which give rise to additional potential difference across this matter maturity wise. So the amount of this OP correct cation is a critically related through the applied to. What we are looking at here is the. Execution spectrum for the one in the second or in this case of active occasion at a different control forty to levels from a zero both to five volt basically at each control voted to level the optical rectification reaches the maximum possible value around eight hundred a nanometer that is the precisely where you have the. Linear absorption maximum. And also the amount of of of purification of course is a critically related to the Apply the voltage levels at the zero both you can hardly see any rectification signal at five o two you'll see a lot. And at a given pump will and so you'll see that live in their current one for the correct occasions to go as a function of the controller both hated the modern nation taps or the model. Magnet. Good for the auto correct cation electricity control the optical rectification is a much larger than that in the previously demonstrated electrically controlled as a cheap because for optical rectification all the signal can only come from the star this is very different from the second harmonic generation we are not only the Parallax the base but also the front pattern the metal film as a contributor to the overall second harmonica generation that is why for this electrically induced modulation their perceived right is very low but hear very large hear very large OK. Another characteristic of behavior for optical duct of creation is the linear dependence of the signal as a function of the for the mental intensity and you see over here actually the slope Chris points to the magnitude of the effect you are quite you in the structure therefore the slope in turn is directly related to the amount of apply the boat in that your voice lets you know why the slope at five forty is roughly twice as a lot as your slope for two point five walked. And now. I'm going to move on to a more suppressive Popovic in one of the metamaterials the so-called or the back or the face matching. The to the longstanding behavior protected by many scientists the almost ten years ago that is still waiting for experimental demonstration OK So just the very brief introduction through folklore the face of Matthew the first matter is probably the most important factor to consider in any learning the way Mixi secretly speaking or the materials are dispersed to you so the conversion efficiency for any one of them will mix is critically dependent on the relation between all the way VAT closely involved there. Let's use the harmonic generation as one example the first matching condition music a tool me. Kill me or you can see. This condition if you really satisfy the by fine tune your intake and the temperature of nano crystals. So off mismatch you really result in a very poor conversion efficiency because of the constructive nor in the conversion only a curve you know very limited the so-called coherence length the Suspend of. The second harmonica and the usual looks like this OK. Or. So that for the manhole light and the second one in the second know how the same in that and they propagate along the same direction. So that for the mental light gradually and the trance depleted along the propagation direction and the gradually. Is converted to the second harmonic counterpart. If of course are big if if the material then learning the material has a negative refractive index there's something really weird. Of course we know it's not given that there will never occur within our broader spectrum. So let's assume OK at the last harmonic of. The refractive index is a negative zero So what is the first measure condition in this case for the way we're after the fifth measure condition is organic. Because it is the cover of the momentum conservation OK one to four times at all got disappear and then you generate a new force and the COS or so each time the key. Poised to be the same at times is to create your model that is why the face matching condition for the K. will have to do like this one but for the refractive index of the base. Condition becomes is this then to me or eco to minors. And they're basically if this is a factor the farther you know there's the second harmonic generation because it was never given that so much here all the all and if you propagation of against the face provocation so in this case generated the Face Mash the harmonious going to will propagate the poor was the force this behavior is a quarter in the backward phase me actually or not in the mirror that was protected by a number of serious to more than ten years ago and they're still waiting for experimental demonstration at offical frequencies. So we try to demonstrate or this we should of course very hard for at least two reasons we know. It's very hard to. To fabricate a negative index so much you're with a very large lens OK many we have learned not to say that you know that you have a second home one of you have to. Tailor the refractive index at a bozo needle and that you'll meet Austin with tenuously so we decided to tempt through this in your way of garden because you know waveguide what's really important is not so much you're in there but the rather more the index so in this case we have a marble more freedom to play with as we can play with you from the moment and we do know how to produce a knack you index the mode your way of God as demonstrated almost seven years ago or one of seven years ago or Harry Atwater's group at Caltech if you have a metal insulator metal we've got it if Mr basin is officially thin and that in that case is a large enough one then the barman into propagating a mold will have a Nabatean Mody index in this possible way of God. So we can carefully tailor the material and the two metal paramita to locate a. Working condition for back of the face and so the metal is the silver on both side and that the locks. Should How was sickness of the thirty nanometer with the refractive index two. And on this picture basically I'm showing you the real and imaginary part of the four the two important more than one is the magical mode that emits the most profound has a in the symmetry in terms of the magnetic field distribution and another one is the medical model. For typical applications you really we always the use this so-called H. symmetrical mode that because of the loss the really low and also the wavelength is relatively large but if you go to the frequency or wavelengths a between the surface of plasma frequency and the frequency so only many hue mode is eight American mode and more importantly this curve shows a negative slope which implies conquer the paired relation between the mode in the face of the last thirty and the crew velocity which he in turn implies a negative one more the index for the mode. So are you play with the other permit Hearst's then we can find unique working condition such that the longer the Omega the for the mental light at the seven hundred sixty nanometer can be faced mesh to the second one is going to offer that is the magical mode at the still hundred eighteen then the meter and the two mode has a refractory in the accept class and a minus three point four respectively. So two two movies OK this helps you to understand the two mode so this is the movie for the for the man home mode as a seven hundred sixteen nanometer it's the same Actually for more than with our poll that here we index and second the movie. Order is the magical mode at a very high frequency of very low will and the more the index is a minus the three point four imports cases the power is along from the left to right so energy always the flow from the left to the right include. In this image so this is the end of the mold as we use implies more in the way of God but in the asymmetrical more you'll see the energy the propagating along this direction of the Free say the propagating opportunity to the energy flow. So it appears that what we need is of something like this one OK metal the electrical metal waveguide. The metal of the silver and then you how Mr Brace are with some of you and the three thirty nine a meter with a refractive index. Actually such a configuration won't work for at least a few reasons one reason is for most are. Metal insulator metal waveguide the spacer is and more force if you will. And more importantly in this case that we are trying to match the H. symmetric for the manhole mode to the H. is the metric harmonic a mode and this two mode has open the symmetry so if you calculated the of the mode over I can factor four as if you correctly is precisely the OK you do the integral for symmetrical mode and the asymmetrical mode of course the answer is zero so basically one way to work this or wrong that is to disable heart of the nine in their behavior in the waveguide the call this was proposed a long time ago almost as a man of my age when people try to match to operate them or that you have the luxury of God you're not in the way of God. So here's my final plan OK. We want to apply a voltage or across the metal to insulate the microwave guide to purposely introduce our response and the way we guide the electric subrace or certain enemy to in total is. A fifteen enemy to each and these are two layers have the same linear behavior but are very different in one in their behavior and a very different election conduct here with here. For the effective response there is basically effectively a boat in half of this hole so in the experiment we have the last thirteen animated talents of a star consisting of two sublayers fifteen enemy to each one being silicon I try the other Y. and have them oxide basically we start with our T.M. a window fifteen and a meter nitride and then do all that have some oxide and then add all the Metallica Prada and electro connection and a salute to the car rules of pop. Film cue for both excited and a collection for the harmonic scale so from the numerical simulation what you'll see is OK This is the amount of the back order or propagated second harmonic generation as a function of the lens off of the mental wave this is the same figure who also shows a face a mismatch as a function of the wavelengths of the mental light and you'll see that indeed you'll see there's a peak for backwards or creating at roughly seven hundred eighty nanometer this is precisely where the the back for the first mention condition. To minors and the fight. So here's the major result from the experiment. What you are looking at here is a spectrum of four the wall heater induced the second harmonica in the region as a function of the pump log and. The amount of water being used as a duty as a function of the Paradis of the incident light you know that OK for such a single Salit light can be efficiently coupled to the waveguide only when it's a plant you could. Do the salute and let you know why you'll see such a behavior. The important thing is this. From the theory we see OK we should expect the back of the face matching to occur as said. One hundred eighty nanometer and the spectral ways for this excite Haitians spectrum of the roughly twenty five nanometer and the from the experiment you will see the peak occurs at seven hundred sixty nanometer with a spectrum of years of thirteen then a meter I believe it's perfectly agreement if you look you experiment on the Syria so we are confident that as this excite hated efficiency peak Chris passed through the back door to face Matthew for second harmonic generation and that he next medium. So. I believe optical metamaterials help provide also with the unique opportunity to realize the very exotic very unconventional behaviors that were not up there over the or even speculated about in the past and that is a very unconventional property also probable cause to rethink and the reevaluate the many established rules in both the linear and the norm in the regime. Moreover I think we should probably go beyond the commission of a commission no mater of metamaterials as artificially structured the mature over the very exotic electromagnetic property as we argue up to a metal material can serve as a self-contained the Amica platform with both electrical and optical functions we should have many none in the light math interaction process including harmonics and the regime including optical rectification can be proposed to be induced to end the Q. in the BY apply the bow to the signals so i should the stank in my previous otherwise and the current collaborators of that show left from pretty you and the mark progress more from Stanford and all the result. Of tender after the year two thousand and twelve. Was made possible through the hard work of my steward in a post talk show from Len. And you know how tree. I know in this our talk I have to ask people many is background and knowledge and the mathematical details so if you have a serious interest. In optical metamaterials you might want to read the book a little bit outdated OK So but anyway I think it's the most important knowledge or mental materials and the very recently to go this book was the lack there of the winner for this year's agreement book writing award so that's where Thank you very much thank. You. And good question Currently we fabricated a structure based on a belief that is upon the pipeline the technology OK so the sample size we have that you are we have is just like a handle of three hundred micro metre in size of that either just enough for auto Maryland OK so if you really want to help with the last few applications of this technology you can use them or they also seem like a like all aligned and then you imprint that might be more efficient but currently. Very small Yes. OK. Good. Actually you don't have to think about too trusting about three What is the norm in there are. Generated even in the process for basically what you are going to have is a crisis really time so the three electrical field component right OK there in this case basically what YOU HOW IS REALLY times the year omega times another year or maker times use the year old is the use the or in the week divided by D. That's why you apply a both heat you get the electrical food the over thirty years across the metal maturity wise OK that either they use zero OK And then this. Eventually you produce some effect your second order response because of what you however or make up plus or make up classes zero which is the true amigo something similar to a second or more of that region but actually it's a start although process thank you. Yes. For the for the Cairo metamaterials. OK or for any good for the. The typical one hundred fishermen fishing that actually alignment is not a problem because the structure doesn't have any dramatic or variation along the direction then basically it has the form of the pattern. And then you do the evaporation of the different layers and then do the lift off you have all the structure automatically so that means perfectly aligned OK for the Sadr October visit. To Mexico variation a lot of the reaction for them or Cairo material that is a very hard Basically you have to we have to rely on other ones to align minute had. Next. You have the first the layer or you what you find all the. Time the markers OK And then you have the first the structure and first layer and then you flat the structure and then do the second online to make sure everything in our mind our great post all who can produce some of the best that material the world the person writing the how to do that. Can. Thank you.