 Our next speaker has studied in Bielefeld and he studied What he did is he studied laser physics and now he's working at the Max Planck Institute for extra terrestrial physics and Today he will explain you how it is possible to lose laser light To enhance distorted images that were taken from the earth of stars and galaxies and nebula So I want to hear a really loud and warm applause for Peter Buschkamp with shooting lasers into space for science All right. Thank you for the nice introduction. Thank you for coming here this evening I'm very excited to speak at the conference. Finally. I find a talk where I can contribute After all those years, I'm not going to talk about Bielefeld. You might want to hear something about that I'm not I'm not allowed to tell you Okay, so Today, I'm going to talk about a bit. What is in my field of expertise? If there's one thing I want to bring across to you, then it is it's not about a single person showing this to you this evening This is a team effort and a real team effort so most of the images are done by a colleague of mine Julian Siegel either and The PI of the project so the leader of the project Sebastian Rabin has contributed some slides and I wouldn't be standing here today and showing you these Images if it wasn't for a huge team and many people and I hope this is reasonably complete But I think there were even more many people have Tributed most and long years of their career into such a project So this is never about something which a single person does and he or she finds something very cool And then saves the world. No, it's always a big big team But before we actually see the lasers then in working We have of course to Clarify why we do this. This is not just because we can we can but There is a reason for that because if you want to get funding you have to write a Reason and a reasonable reason not just because we want to So in the first part I will introduce you to the whole thing and we'll talk about a bit About the problem, which we want to tackle with this kind of technique I will mostly present only Diagrams not actual hardware blocks already so that you get the the basic concept So when we do astronomy We do two types of things we either do imaging which is we maybe produce a nice image of a star So that's a blob over there or we take this image. Maybe this little Blob over there and make it into a spectrum. So we disperse the light and then we look at at the differential Intensity between the diverse colors or other other maybe for example, you see black lines in their absorption bands and and so on To do such as thing you need a spectrograph and in a spectrograph. There's a thing called an entrance slit So in this slit you have to put over your object So that you don't get light from left or right next to the object to what you want to observe or analyze So that you only get light from where you want it the thing is now this slit cannot be made arbitrarily wide or small because the width of the slit Directly determines what kind of resolution you have in such a spectrometer as it's called This is a quantity which needs to be above a certain value when you want to do certain kinds of analysis So it has a fixed width So now if we look at an image produced of one of the most capable telescopes on this planet and we put a Representation for the slit over the star. Okay, now it's white. Let's make this black Then you see if you want to go for that star over there You do have a problem already I said you can't make the slit wider But the the star is actually larger than the slit meaning that you lose light Well, and you lose some light. No, if you want to do quantitative measurements, you want to have all the lights and all the pixels So you can't get rid of them and just throwing something away So but our image is looking like that. It's maybe nice. So But can we do better? Yes, we can and this is what we can achieve with adaptive optics This is an image that has been produced with adaptive optics with a laser A o-assisted system and if I flip back and forth you see there is a difference alright so Why is that why don't we get this ideal images? The reason is because there is the atmosphere the atmosphere is great for breezing It's not that great for astronomy So if you have a star up there somewhere in outer space can be very far away So the photons might have traveled for 11 billion years and now they finally hit the atmosphere and then something happens Which you do not want Okay, first they travel freely. There's a nice planar wave front. So it's not disturbed by anything Maybe something but that's not the scope of this evening. It's planar. It's nice and If you actually have a satellite, it's very cool because then you can directly record this undisturbed light If you have something on the ground Well You do get a problem because the atmosphere introduces turbulence because well the air wobbles Wobbles a bit. There are streams coming from all directions. They are temperature gradients in there and these all Work together and make from this nice planar wave front a crumbled one If you have a perfect image Which you create this is called diffraction limit. This is just limited by the size of your optics So the wide eye your optics is the nicer the resolution is of your image if you then build a large facility with maybe two Eight meter mirrors on the ground. Well, you only get a seeing limited Image seeing limited the seeing is this wobbling of the atmosphere as it's called And that's about it. You can make it arbitrary large You won't get a better resolution than a backyard telescope of having 20 centimeters in diameter so Yeah What to do there have been people of course thinking about this problem longer and the first idea came up in 1953 and some guy at Palomar Observatory in California Said well if we had the means of continually measuring the deviation of rays from all parts of the mirror and Amplifying and feedback this information so as to correct locally the figure of the mirror in response to the schlieren pattern We could expect to compensate both for the seeing and for the inherent imperfection in the optical figure what So if we could somehow Get rid of this wobbling or counteract that then we good could get this perfect diffraction limited Imaging we get in space also on the ground In the 1970s the US military started to experiment on that. Well, I guess the Russians too, but it's not yeah It's it's known that the US started at Starfire optical range In 1982 they built the first system a OS system adaptive optics system The compensated imaging system on Hawaii and in the late 80s the first Astronomical use adaptive optics systems come on as it was called installed at the observatory of Provence and At iso in La Silla. That's the European space Observatory Alright, so that was yeah, we get from this fuzzy blob actually we found that this fuzzy blob is not a fuzzy blob But two fuzzy blobs Well, it's a binary system as I would say it if this was yeah at a Astronomical conference, but yeah, you this entangle things you cannot you could not see before Okay, how does this a OS system look like in principle? So again, we have the stars somewhere We have learned already that we do have actually you see this Slight Leon pattern in the air from the warm and the exhaust from the Yes, there's a bit of flimmering in the background and that's that's seeing Okay, so the image is not as sharp here as it comes from the projector there Okay, that comes from somewhere and then we need a system which has three components One is a deformable mirror The other is a wave front sensor and the other the third one is a real-time computer We need something to actually measure what is going on then we need to take this measurement and extract some information from this Measurement and then we need something which can correct this way front Straighten it out so to speak because we want to have it straight again So the way front sensor sends some information To the real-time computer this some information namely is what is the curvature? how does this wiggle thingy look like the way front and that real-time computer computes then information that goes to the deformable mirror and that is in real-time shape to an arbitrary shape counter acting that Incoming way front and then straightening it out So we do have a light path like this first so it goes on this deformable mirror goes on something else Which I will come to in a minute and then on this way front sensor and of course that means if you run it You do have a Control loop Meaning you measure something here at the way front you put the information into there feeding that into the deformable mirror that deforms somehow Modifies this Wavefront that comes from above and then of course you want to have a feedback loop Is that what I did enough do I have to do more and also of course the next In the next second or split second this pattern will have changed because the atmosphere is dynamic If it wasn't dynamic, we don't need to do this in real time but we have to do it in real time real time meaning we have to do this correction and Calculation and sensing at a rate of about one kilo Hertz. So a thousand times a second Then we have a scientific instrument because actually we do want to see What is in there and so this thing in the middle is a beam splitter It lets it takes some of the light puts it to the wave front sensor Not all because most of it should go into the scientific instrument and there as you see here Then the way front is straightened out again, and then I can focus it into my instrument to do actually that I have to do this is the one slide in the start with a Greek Sembo You have this incoming wave front Which is shown in orange and then you do a piece wise linear fit Which is an approximation of the slope of it actually how it looks like it's Put into linear pieces and this the size of what is normally can be taken as a linear Fit piece is roughly 10 to 15 centimeters for good observation sites While this thing be here. So this is the primary mirror of the telescope which collects all the light that comes from Outer space is usually for the big telescopes At this point 8 to 10 meters Okay, but how do we get this slope now? We know that we can approximate it in pieces, but how do we get the slope? Because we need these slopes of course fed into this Deformable mirror to maybe okay if it comes like this I go like this and it comes in nicely or comes out nicely so on this way Sensor comes in that different types of these sensors But the one we are using is a show so-called Sheck Hartman sensor And it looks like this We have this the ideal case of course so we have an incoming planar wave front straight on Then we do have an array of lenses. So it's just one two one two three four lenses And then in an array like four by four and They all focus what is coming in into onto a detector And if this wave front that is coming in is planar like this on the left Then you do get a regular spaced grip of focus points in this case for times four so sixteen If now the incoming wave front is not planar it looks like this So the focus points do move a bit because well it came maybe like this So the focus is offset. I will flip it back and forth again. So it's looking like this and You see of course you do know what is perfect Meaning they are they are at their designated grid points if it's imperfect. Well, well then just Measure the deviation from their zero position so to speak and then you do have a proxy for this slope Of course, it's a bit more complicated than that. There is our matrices involved which are not necessarily Quadratish and you have to invert them and if you don't yeah They're pretty clever people and programmers working on these type of Of problems and this is actual current research. This is this is far from done this field Okay, so suppose we do have the slopes Then we take a deformable mirror and this is the zero Approximation zeroes all the approximation of a deformable mirror. Let's say your wave front looks like that Well, then take just a mirror, which is maybe recessed a bit in the middle the other type forward It bounces on this mirror and because there is something sticking out there and in there Well, if that approaches there goes back and in the end the whole thing when it has been reflected Is planar again? Okay, that is well as said the easiest order approximation for that. It's a bit more complicated your Incoming wave front doesn't look like that. It's more more normally a bit more complex and That means you do have to have more Wobbling in your deformable the mirror you could do this that's in the upper Diagram you could do this with a membrane which is continuous or maybe it's also in pieces And these segments are driven up and down or maybe tilted by piezo Stages that are put underneath Remember they have to do this like a thousand times a second Or you could do something like you take a two piezo electric wafers They have opposite polarization put electrodes in between and then when you apply a voltage to these blue electrodes Then you have local bending so the one thing will bend up The otherwise will bend in the opposite direction and then you do have changing curvature on this whole thing it's not that easy of course in reality because They are not completely independent one cell will influence the other and Yes, but this the basic principle, okay Now you have seen there was this believe beam splitter so most of the thing goes into the science instrument And some goes to our wave front sensor of the light if the object We want to record like a galaxy that is 11 billion light years away Then this galaxy is too faint. We can't analyze its light So what do we do? We need maybe a star that is near bright so our galaxy which we actually do want to observe is the red thingy The bright star is the yellow one and if they're reasonably close together reasonably close meaning about 10 to 20 arc seconds if you stretch your arm and look at your Little finger at the fingernail. This is about 30 arc minutes One arc minute has 60 arc seconds, so it's very close. It's not the galaxies there and the stars there. No, it's there Because if you have a large separation then they do sense different turbulence simple as that Now the thing is that less than 10% of the objects you have on sky Which you're normally interested do have a sufficiently close and bright star nearby So what to do and now we come to the lasers Because if you don't have your well if they don't want to play nicely well build your own theme park with yes, you know so Make your own star This is what we do because if the star is not nearby a sufficiently bright one Well, why has it to be sufficiently bright because if you want to do this computation a thousand times a second Well, then the time you can the time for your CCD Where you record this image from the wave front well is A thousand of a second and if you don't have enough photons in a thousand of a second Well, then there is no computation of this offset of this little green dots on their grid So you need a lot of photons So let's get enough photons and there are actually two things what you can do There is a conveniently placed sodium layer in the upper atmosphere It's 90 kilometers above ground and there's a sodium layer and What you actually can do is you can take a laser on ground here and then shoot Laser which corresponds to the energy transition of this sodium atoms Which is five hundred and eighty nine point two nanometers. It's orange And excite those atoms up there in the atmosphere and they will start to glow and if you have a focus if you focus it in there and then you have a Blob of sodium atoms lighting up in the upper atmosphere maybe whatever some hundred meters long and Some meters wide as big as your focus is there. This can be done with a continuous laser This has been done in the past. Yes, of course and actually the first Instruments were built like that The thing is in those days. They were very very expensive. There's no sodium laser. They are only Die lasers and they are messy and expensive Nowadays we can build this as fiber lasers, but not 10 years ago or 15 years ago Another solution is to actually use the Rayleigh scattering in the atmosphere you use a Neodymium yuck laser which is five hundred and thirty two nanometers is green. It's easily available. It's cheap compared to the other one and Then you focus it in the atmosphere. The only thing is You will do have backscatter of photons all along the way So you have to think about how can I only record light from a certain height above ground? Because otherwise I don't have a spot because I have a laser beam column somewhere there Okay, how do these things look like can we dim these lights actually a bit or is there is it only an off switch? Can you check on this thing? Yeah, let's let's check on that. Let's just just push the button. Come on No, no No It's still on here All right, it's looking like this who has been at the camp There was an astronomy talk at the camp from Liz Okay Actually if this talk had been tomorrow We would have had a live conference to that size because Liz is right now here and she sent me that picture Just some hours ago. That's how they just do things on Paranal in Chile The thing I will talk about is the green one to the right. That's the thing I have been involved with Yeah, let's look into that so if you shoot the laser into The atmosphere of course you do have a problem the star is very far away is infinitely far away and the light that comes Down is in a Cylinder and if you shoot a laser up, it's a cone So you only probe the green region and the unsampled volume of turbulence is to the side That is a problem with our laser AO another problem we face is this one when we take a star to measure the Wavefront then it passes only once through the atmosphere the laser beam goes up and down and so there is a Component called tip tilt component, which is actually just the thing moving around It's not just this the face That gets disturbance that's being introduced in the way front, but this moving around not the soul not the bright and more or less bright Twinkling little star thingy, but the moving around and that can be not be sensed with a laser guide star So whenever we do laser AO we do need another star to get this component But this star can be a bit further away like an arc minute or two arc minutes or so so it's that and that is why there are enough and Then we should think about actually what we have to correct and so we should make a profile of the turbulence above ground and this is how it looks like and for example for the site where we are there in Arizona we see that most of the turbulence is actually just above the ground So we maybe should care mostly above the ground layer. It's not so much about the high altitude things So and then what we do is well we want to sample the ground stuff nicely. So we just don't take one by three lasers So to fill This area nicely and yes, of course, we can also combine this and it looks like that This combination we will not talk about today. We will only talk about that This is how it looks like so this is our telescope the primary mirror which receives the light from Outer space it then deflects on the secondary tertiary and then somewhere here But first we need to have to shoot the laser up and it's move the launch from a laser box onto a mirror behind that secondary mirror over there into the atmosphere and after 40 microseconds it reaches an altitude of 12 kilometers and Of course it comes back after 80 microseconds. It's here in our detector again So the star then lights up Has this cone gets focused they are focused reflected to here and We do have our signal in our detector after 80 microseconds and as said because of course the laser Has scattering all along its path you will you want to gate this information to 12 kilometers And well, then you just just look at when your laser pulse started Wait wait wait wait wait wait wait wait wait open the shutter for the detector for a short Time after 80 microseconds close it again and then analyze and read out what you just did Easy, huh, so we're done Thank you for coming to my talk and now go out and build your own lasers with to Now we're going to look at this thing Which is actually built and which works? So this is called Argos It's a ground layer AO system. That's what we want to build it has wild field correction That means you cannot correct just a tiny patch on sky, but for Astronomical use a huge area Meaning it's not just a circle of 10 arc seconds But this thing can correct 4 by 4 arc minutes, which is huge. So all the objects that are in there We have a multi laser Constellation we have seen that why we need this because we want to fill the complete ground layer. So we have three Laser guide stars per eye by per eye. This will be clear in a minute and we use high power power pulse green lasers and This deformable mirror is actually built in the telescope system already The secondary mirror is the deformable mirror, which is very convenient because then all the Instruments that sit on the telescope can benefit from this System it's installed at this telescope looks pretty odd. Yes I admit that that's the large binocular telescope. It's two telescopes on one mount one primary two primaries It's roughly 23 by 25 by 12 meters. It sits on Mount Graham in Arizona And it has an adaptive secondary mirror, which is this Violet color Thingy up there in the middle on top. This is how it looks like This is the control room where you sit this is This stays fixed all these shiny part rotates. That's the actual telescope the red thing that moves up and down So the whole building rotates and move up and down It's from the Ceiling as is at level level 11. So when you actually sit there You can Watch Around a bit so that okay, that's outside. It's winter Okay, let's see and there you there's a letter. Okay. Uh-huh. Yes, this thing is huge. Yes, okay Okay, that's how it's looked like when you are when you're actually there Okay, our system layout is like this We have this secondary adaptive secondary mirror, which is the deformable mirror We have the primary tertiary that is clear already. So we have a laser box The green thing is being the lasers themselves So that's how it looks like we produce some laser beams We have steering mirrors in there to get them into the right pattern on sky Of course, we do have control cameras if it's is the focus right is the position right? This is one a control loop another control loop another control loop another control loop The black thing is the shutter because we have to close this whole thing when Aircrafts are overhead when satellites are overhead. So if you want to use this system, you have to Put six weeks in advance. You have to put out your list of observable Targets to some military agency and they will tell you okay. Not okay. Okay. Not okay. Not okay. Okay Not okay. Meaning something is passing overhead. What could this be? Hmm Of course at some point the lasers come down again in this cone shape they will reach the primary mirror and Ultimately it will end up in the wavefront sensor, which is much more complex than just this box I Showed you before so there are acquisition cameras which detect are we at the right spot do the Sports get on to the detector in a nice in a nice fashion. We do have to do this gating Remember we have to open this shutter for the CCD when we want to record the light for this tiny fraction after 80 microseconds After the laser pulse has been launched That's done in here. These are pocket cells. So it's an electro optical effect and then there's also something in In addition because well I said we can't do without the tip tilt and there's another unit in here That sits right in front of the science instrument that detects this tip tilt star this additional star and so you have the Laser wavefront light the green one you do have this tip tilt light the blue one and You do have the actual science light from the object You want to observe on sky that goes directly into the scientific instrument in the end and then you have a lot of control things of course you do need a common clock for this Synchronization of all these pulses and the gating and whatnot and Of course you need the information for the tip tilt component and for the wavefront Into this computer which sends then all the slopes. You remember we have to do this linear Proposemation piecewise. Yes Into the secondary mirror which then deforms in real time and does this a thousand times a second This is how it looks like So when I'm there, I'm roughly that tall The two black tubes right in the middle those are the two tubes which go up Looks like this So this is how the components are distributed over the telescope Once back. Okay primary mirror primary mirror some instruments in the middle some tertiary mirror The secondaries the adaptive ones up there Yes, I hate to use I hate to use these These these laser pointers. I know no no no no because I'm always going like this And it's my man So, okay, so we do have the So we do have the adaptive secondary up there And then it goes back on the tertiary down there and then goes over into the science instrument or the wavefront sensors and whatnot Again we do have a laser system We have to play somewhere a launch system for the laser a dichroic to Separate between the laser light the tip tilt light and the science light We do have to have a wavefront sensor to check how the way friend looks like we do have to have this tip tilt control We have it. Yeah a calibration source would be nice to calibrate the system during daytime aircraft detection. Yes Satellite avoidance also an issue and a control software There are many people just writing just how writing software for this and this is this is really hard Some are also on this conference They don't want to be pointed out as I learned but you will find them at the conference if you look at the right places That's where the laser box is located Just next to it is the electronics rack Um, how does this thing look like so that is our one of our lasers? It's about 20 watts Don't get your finger in there. It really hurts and If you know There's a mandatory annual laser training, of course Yes And if you want to have something like this at home You do need a huge refrigerator next to it just for the cooling of that thing This is nothing you want to have at home just because it's it's it's that bulky. It's nothing. No, it's it's no It's not because actually when you do this green laser pointer thingy Then there's always this yeah, don't use it for more than 10 seconds Because why because the crystal inside heats up and if you can't dissipate that heat the crystal at some point Breaks and then your laser pointer is broken. This thing gets continuously cooled. So therefore, it's a bit more expensive If you then put it up So this is still on the lap table when it was integrated and tested and then at some point It gets put all in a box with all this control mirrors and cameras and whatnot but finally you see in the middle on this picture there is a Focusing lens and then you see these three tiny little beams coming out of there which then expand on sky well like in that size, of course If they're in 12 kilometers height But that's how they come out of it and if you Install this and the telescope you actually have to tilt the telescope because otherwise you can't range it and then you need your climbing gear So once you have produced the lasers you need to propagate them to through a dust tube Onto a lounge mirror Folding mirror and from there to a lounge mirror Yes, and then look like this Okay So the lasers come from here into that and then over to the other side over the Secondary mirror and then being shot right up into space like this Okay, so if you want to have that at home But I can tell you the whole facility does cost less than one fully equipped Eurofighter. Okay Thank you for taking the hint. Yeah, that's how it looks like It's yes, it's Yeah, yeah Okay, I have to admit these are a bit longer exposures It's not that bright and green when you are actually at the telescope up there But if you have been in the dark long enough around ten minutes, then it really becomes bright There's a little telescope that observes where actually the spots are on sky And if we have clear sky, then we have this constellation on the right So that is how the lasers come up as said they use you do see them all the way up But we are interested in the little dots at the end you can barely see them if they are high clouds Well, then we could use something like this We have the Detroit dichroic when the light comes back down as said which separates the science light in red and the laser light in green This is how it looks like Actually, the droid is right in front of the bust on there And from there it gets then reflected on a reflector and then up into the wave front sensing unit So there is the dichroic There is the reflector and it goes over in this unit, which is the wave front sensing unit Which it's there at the side That's how it looks when it gets installed and that's how it looks inside So you have the three laser beams coming from the side from the sky, of course You have patrol cameras which monitor where are these are there at the right? Are they at the right spot do we have to steer the lasers a bit? Then we have some control For the position of the laser spots and the field The pocket cells are the ones that do this Opening and closing in front of the shutter you can't use a mechanical shutter in front of the CCD We have to do this Optically, so you you have a polarization of the laser beams and you have a polarized Polarizer across polarizer and then you just turn the polarization of the crystals It's an electrooptical effect and then it gets passed through or it gets blocked Then you also of course have the lens lit arrays in there and then the CCD Which actually records this dot pattern you remember this four by four Well, it's not four by four in our case. We do have a bit more resolution The sensor reads looks like this. This is actually a custom-built CCD Very special the imaging area is in the middle and when you read out the thing You split the image in half you transfer it to the sides to the frame store area and then read it out Because read out is slow transfer as fast and you have to do this a thousand times a second at very low read out noise Which is only for electron read out noise For the experts here in the audience this is very good It's not many pixels, but it's more than enough for us. So how does this look like looks like that? So there you have your pattern again your regularly spaced pattern of course from three laser guide stars you get three patterns and then you analyze well the position the relative position the absolute position of those dots on their grid and somehow Compute these slopes from there feed them back into compute them actually Electrical information from them which you can then feed into your deformable mirror again Which sits on top of the telescope and then hopefully everything works This you can digest at home It's in the stream now, so it will be safe for all Eternity and all the aliens which record the electromagnetic field from like Anyway, so Just in short there is Down in green. There is this thing that goes up from the lasers to Through some steering mirrors. We have diagnostics and we go to a focal focus Check a lounge mirror one and lounge mirror two onto sky and then we go back Up there and one is the primary mirror And then we go through this whole chain and there are various control loops sitting in there And all these things have to talk together on very high rates Sometimes you see one kilohertz other things are a bit slower, but this all needs highly sophisticated control software and The programmers can be real proud of what they did in the past with all these control loops The tip tilt is very is much much much easier because well you remember this tip tilt So just the moving around so you have four quadrants at a little cell And if it moves to somewhere up down left right you can easily detect that and that is fed into a Array of four avalanche photo diodes To actually record this and for that we don't need many photons So this tip tilt star can comparably be be comparably dim The calibration unit for daytime calibration can be put into the beam So these arms can swing over over the primary mirror and then we can inject artificial stars via a hologram Into the whole unit during daytime and calibrate this whole thing and then yes, we are back here This is how we look like and And Yeah, maybe concentrate on these two Areas first I Will flip back and forth many times But yeah, what is this are these two stars which are just fuzzy and dim or is this an extended object? The upper one may be a galaxy because it's elongated Okay concentrate on that No, it's actually just a bunch of stars and this is over a huge field So the the correction is not just in the middle But you can see also at the very edges of this image We do see this improvement in image quality of course you can have the diagram if you want So the blue line is without the thing being activated open loop and if we close the control loop to do this Measurement and correction in real time. We do squeeze all the energy into very Few pixels which of course also mean our signal to noise level in a single pixel goes up tremendously meaning you can decrease your exposure time Which is important if you want to observe galaxies at these telescopes It's two hundred dollars a minute. It's not cheap Okay Good. So the thing Just last week There was another commissioning run testing commissioning run for the system and my colleagues Rossi Borrelli and Lorenzo Busoni have done a nice video the music by the way. Hello gamer It's royalty-free So if it knows now darker therefore asked This would come up nicer, but let's see there is sound hopefully so the sound guys Let's see. Of course. This is a longer exposure. It's not that Star Wars like I Would have loved to use some Star Wars tunes along that Yeah, you know all these rides and whatnot. Yes anyway That's how it looks like so you have three laser beams per eye per telescope remember we have two telescopes on one mount they look roughly in the same direction but still So if you observe on two telescopes at the same time, it's only a hundred dollars a minute. Yeah, this is Well, not so much the shiny part on the dome itself but if you actually do stand on the mountain during night and are a bit dark adapted you see the laser beams like that and Don't be fooled if you are at the valley or Very far away you hardly see them You don't see them at all you see them there if you are two kilometers off-site already It's merely a dim greenish something if you are down in the valley ten kilometers off You don't see them anymore if you take a camera five minute exposure. Yes, but otherwise no There is no such thing as the people in the valley down Can see like these laser pu pu every night and no No, nothing Okay Which gets me to the last part how? Do you become and how do you work as a laser rocket scientist? Yes, I put this in the talk directly because I do get this question in the Q&A normally when I talk about these things and It's always like what do I need to do if I want to do this? and Maybe you have already an idea about this because you have seen how complex this thing is and There are so many things to do in these kind of projects and on various levels also in administration also being senior people new people maybe master Theses works on that or Bachelor or PhD or then as a postdoc. It's very complex. Yes, and it's not only about just shooting the lasers in the end Sometimes it's just checking the cables Yeah, but it needs to be done There is a tremendous amount of electronics and electrics involved there are all the mechanical components in such a system are custom-built Either the institutes build themselves or they give it Out of house. There are these real-time computers for example This is by the way our real-time commuter from micrograde if you want to look that up. It's a company Who builds these things they need to be programmed and Oh, actually if somebody is here in the audience with really hardcore experience on real-time computing coding on such thing He's do talk to me Yeah, this is how our software system looks like a very small part of the GUIs it's a lot of it's a lot of code and a lot of work and a lot of sleepless nights in front of these Computers and just testing it and testing it and then testing some more and testing even more and So to be involved in these kind of projects. You don't need to be a laser physicist Because there is no one thing If you want to take one three messages out of this it's it's a team effort There are many tasks and there are many jobs and you have to pick one Because in this one job you do in these projects You have to be very very very good because there are other people that are very very very good If you work in these kind of projects If you meet a new person for the first time just assume that he or she knows everything about this And you know nothing you will soon you will quickly realize if it's if that is true But otherwise if you it's in with the other way around you just make a fool of yourself, okay Don't do that people in science Second most important thing if you really want to go into this people in science are just like people outside science Meaning you will meet nice people and you will meet Just like in life It's not that these Things are spheres where people are you know floating above the lap for surface in nice colored No It's hard work And if you actually go into this like study physics or maybe If you want to construct these of of course the all the drawings are done by people who have learned this in their studies So machine bow whatever Go for that one Building optics needs optics experience if you want to actually build stuff Well, there are many people in these institutes or universities who work in the mechanical fabrication departments or electronics departments. They just do PCB layouting all the time But these things do need Sophisticated electronics and this is all custom-built. This is nothing you can buy off the shelf nothing of it almost nothing And this means you might end up at something equally cool It's not that you can have this one thing and then Bam ten years later. You will be the laser rocket scientist. You won't you might become one and then Even after ten years you might realize this is not the thing you want to do forever So I have to correct the introduction in one point. I'm no longer working there. I recently left and Now have my own company. I'm still involved in these things I do calculation for these two kinds of things, but I'm not at an institute anymore because I decided for example for me that the Contract conditions in this type of scientific work are not of the type which I Want to live with anymore like one year contracts And so there are many ways of being involved in this and don't just don't just focus on this focus on what you Really want to do and you might end up in this and if you don't Well, you do something equally cool. First of all, thank you for our daily dose of lasers I have a set set you have kind of sad news because we have really not much time left to a Q&A so I'm first asking the signal angel if there are any questions from the internet because It's what's that a to Okay, because these people can't ask questions afterwards So yeah, I'll be all Congress and if you want to reach me directly 7 3 1 9 is this telephone Okay, so the signal angel questions Yeah, the first question from the internet was how strong the laser actually is or it could be any danger for something in the vicinity Actually, no, so we shoot up around 15 to 20 watts per laser beam If there was actually a plane flying through our laser beam then Nothing happens to the pilots. They don't get blinded or whatnot because it's The beam size at that altitude is so big already They will of course look like what is this and that's what we don't want one because then they might push some other buttons Which they're not supposed to push If you of course work directly at the system you have to maintain it you open it you have to Align the lasers and whatnot beyond the that they're self-aligning capabilities You do have to wear all this protective laser goggles and whatnot because if you do if you don't you do have instant Eye damage is not that No, it's instant. You don't might you might not see it instantly, but the instant It's there instantly period so really folks Don't experiment on this laser stuff at home if you are not following basic laser safety rules Not prying these things from the DVD burners and whatnot Blu-ray thingy. Does it really work? Just don't it's your eyesight is not worth it period. It's not Please remember to cover your still working eye Yeah, only look into the laser beam with your remaining eyes The other question and the second question from the internet was It was actually commenting that it's a very cool concept already in use and where do you see this going in the next ten years? So what's the outlook for observation from the surface in the next ten years? Oh, of course the telescope will get bigger and bigger the next generation of telescope is coming up in the 2020s the European extremely large telescope will be Roughly around 40 meters in diameter. These are so huge. They can't work in seeing limited operation anymore They do have to have Laser a o all the time it will look similar to this so this is in this sense also a technology demonstrator There will be a combined thing You remember this diagram with the one sodium laser in the middle and the others outside So these combined things and then you can also imagine something that you probe different heights in the atmosphere because you do have different Turbulence layers and all of these then have their own Deformable mirror so it's very gets a very complex set of multi-conjugate AO as it's called and then there are of course new There's research being done on how to detect this wave front most efficiently And there's a so-called thing called the pyramid sensor You can look for that also we do have one in our system and this is very efficient So it takes much less photons to get to the same signal to noise level it this is active research and well every major telescope of course now has this and every big telescopes in the future will have this All over the place Okay, we're completely out of time again. So again, thank you very much you