 Okay. Okay. I'm here. I'm online. Hello everybody once more. Today we will continue with polarization microscopy, namely polarimetry. Yes. And I think that our experimental demonstration consists of three parts. On the first part, it's an explanatory part about the construction adjustment and so on of a miller polarimeter. The second one, the second part will be about obtaining images and using statistic analysis in order to analyze them. And the third part will be about calculation of all necessary parameters such as, as you remember, stocks vector parameters and miller matrix parameters of such a biological speachman. So here I propose that group number four. Yes. Yes. Group number four. Everybody from group number four, come to the table. Please be my guest. I started. So I think that I switch off the microphone. No, because the video recording. Okay. Okay. Nice. Yes. Please keep window for this, for camera. So Victor, if anyone want from other group, group number five will be the next, should be the next. Yes. How many students of group number five? Okay, please. I think that it, yeah, please. So here, here. Okay. Okay. Okay. Okay. Okay. Not too much. How do you think? I think that it is enough. Yeah. So please, a few words about the technique of safety. So please do not touch some parts. Yeah. And if you want to do this, please ask me. And yes. So here you can see the optical scheme here. Yeah. And here. And this one is an experimental prototype, maybe laboratory prototype of polarization microscope, namely Mueller polarimeter at all. It consists of laser here. It's number one. Here you can see collimator and quarter wave plate to this. It's for creation of collimated beam, but due to the complexity of border crossing and so on, these parts are missing here. But it is no problem because we have pretty nice laser beam from this laser. So it's pretty collimated and it can be used for further experimental demonstrations. So here, this one, this element, it's a precise rotator for a polarizer. It consists of polarizer. You can see it here. Yes. This one. Yeah. And this mechanically movable quarter wave plate here. Here. Okay. You can, if you want, you can. No, no, it's a few seconds. I don't think that it will be crucial. Yeah. So, yeah. So polarizer and quarter wave plate on this scheme, it's, it's correspond. Yeah. Polarizer five and mechanically movable in this beam and removable from the, from this beam, this quarter wave plate polarizer. No, yeah, wave plate is not rotatable. It's in a stable, in a fixed position. So it will be a little bit later. Thanks for the question. Here you can see imaging system. This is a specimen. It's a histological section of human myocardium tissue with all necessary agreements and so on and so on. Here. Yeah. You can see it here. And this is a polarization micro objective. Polarization means strain free. It should be strains free without strain in the glass cause in order not to not change the polarization of incident beam of this unit, four and five, yeah, cold polarization state generator ESG. The next one unit, this one, it's a polarization state analyzer. It consists of, you can see it here. It's just similar to this, the same polarizer nine. Yeah. And quarter wave plate eight. Here's the CCD camera. Tony, ICX, DMK. It's not very important, but there is a few, a few, a few demands. Yeah. For example, for this, this camera should be linear, should be linear in the dynamic range of this laser illumination cause it shouldn't be, it shouldn't have some saturation. Yeah. The linear characteristics might, must be, might be this one, not this one. Yeah. So, you know, cause in, cause in this region, all for example, values of intensity will be the same, but in, naturally they are not the same. Yeah. That's all. What we do, what shall we do the next? On the next stage, on the next step, we should adjust this setup. For example, we should know or we should get the optical axis of corresponding polarizer and analyzer. For example, here should be zero and here also should be zero. What, what is the procedure of such a, so here is the program. Yeah. You can, this is, you can see mean value of intensity of whole intensity. This is a maximum value of some pixels. We should, for example, if we, this is already collinear, but if no, we should here get a 90 degree and in general the signal should be zero. Why? It is not zero cause light here. So, this is quite nice zero. Nineteen. Yeah. Nineteen. Here. Okay. Here we have a 90 degree and or, or we should put here 90 degree and after that by rotating of this inner analyzer, we should reach the minimum signal. In this case, this polarizer and this analyzer are crossed. Okay. The next step, we should adjust for the first time this quarter wave plate in order to define the optical fast axis of this quarter wave plate cause it is not rotatable but fixed. So, you know when the polarization plane of incident beam, yeah, illuminating beam coincides with the fast axis of quarter wave plate polarization doesn't change. So, when we introduce this quarter wave plate here, yeah, we see the same due to the, with respect to the illumination, yeah, the same results. So, if no, we should adjust it by rotating. So, at this time, we know that the fast axis of this quarter wave plate are the same with this analyzer and this polarizer. Very, the very same situation for this one. Yeah. Okay. In this case, our polarimeter is adjusted. Yeah. So, yeah. Okay. Good. So, at the next stage, we should introduce our sample, this one. Yeah. Yeah. Here we can see an image. This is, as you, excuse me, one moment, nice. Here, the adjustment for focal length cause in order the different samples can have different thicknesses, the focus lengths can change. So, we should adjust it manually. Here, it's not focused, yeah. And here is not focused. Focus is just here. Yeah. Yeah. Once more, a little bit. Oh, okay. Not, not, uh-huh. I see what's the problem. Not, not, not, not put cause it is not a really optical table, yeah. Not a standard, but yeah, nice. As, as you hear from previous, our previous lecture, this is my cardam tissue, is well ordered tissue, yeah. You can see it separate fibrils that are aligned in this plane, yeah. So, we talked about the optical activity or anisotropy of such a sample. So, how we can check this situation? We are, we can cross this polarizer with this analyzer and see what we will have. Yeah, nice. You see? This is this one. It's so called polycrystalline structure. So, these components are purely polycrystals maybe, but crystals in very small regions, but here you can see that in, in not the very small regions, yeah. This is a structure of soft structure of our tissue without water and so on. Okay. This is the help of this program. It can be, it can be, you can use different programs, but this one is very useful. Okay. Here is a pass to our images, this one. Here you can load, let's, let's take several images. This one is for crossed, yeah, this situation. Okay. And this one, we should analyzer link. This is collinear state. Yeah, here the intensity is much higher here. Yeah. And also, okay. We get these two, two images, polarization images. You should know. Here are in the, in our pass is the temp, yeah, temp here. You can see two images for a collinear state and cross polarization. Okay. Let's do some statistic analysis of these two in order to, to see what is histograms and, and the statistic moments. Here you can see a MATLAB program. Okay. We can, we should copy these images to the other directory here and from this MATLAB script. Here you can see these two images in JET. Yeah, pellets because JET pellet is, is very attractive. Here you can see the values of intensity from zero to two hundred and fifty five, yeah, for a collinear and cross polarizer and analyzer. Even here you can see the polycrystalline structure, yeah, in, in red color here. You can see it here. For the, some types of, of uh, diagnostical investigation and so on. For example, if we have some big tumors or something like that, if you want to have, to, to see the polycrystalline structure purely, you can use even this one. If we, for example, if we use several samples, you should, you should provide some objective parameters in order to compare between of them. For example, for the second one, you can see it here. It's a collinear, yeah, the first photocollinear, polarizer and analyzer and this is a histogram of distributions of the values in this picture. In the, in another picture you can see this is polycrystalline structure here. How to describe these distributions, yeah, yes. Program we have, have, have know about statistical moments, yes, from the first to the fourth orders, namely average value, dispersion or standard deviation, skewness coefficient and kurtosis coefficient. They are calculated in MATLAB and in this, the directory called results, you can see it, yeah, that zero, zero is collinear. Here you can see it, yes, namely, and you can see, you can see it here. So this all, all values, standard deviation, dispersion, skewness coefficient, kurtosis coefficient, median. The mean value is the following. For the crossed polarizer analyzers position, we have the following. So if we have several samples, which are close one to another, we can use the differences in this higher statistical moments, namely skewness and kurtosis. You can read it in my publication when you enter Yuri Ushenko and so on, but the, along with this statistics of particular sample, you should have the statistics of samples. You should have sufficient number of samples in each group. It depends on the structure of the sample and so on and so on. There are several criteria in order to understand what is the number of samples should be, because the root mean square deviation of these statistical moments should be in the group, should not be bigger than 0.025. And this is a criteria. So you can, you can read it in, for example, in a medical diagnostics books of forensic medicine, you know, forensic medicine. It's a very powerful medicine, the final, final and the very precise in other case. Yeah. So this one. Okay. What about, it's about just a few, few measurements about in collinear and cross polarizer analyzer. We, in the second demonstration, we should talk about the field scattered by such as samples here, yeah, on the plane of CCD camera. In order to describe this field, we should define measure and calculate it for stocks vector parameters, namely the first one, second one, third one and the fourth one. The algorithm is here. So, excuse me. Okay. What should we do? The first step, yeah, there are several steps here. The first step is already done. We have measured E sub zero, yeah, and E 90 sub 90. So just, just right now. So let's do the second and the third step. What, what, what is the core of the second step? We should measure here intensity of 45 and 135 degrees. Yeah. So let's do this. Firstly, we should arrange here 45, this one, and measure it. Okay. This one. And after that, we should rotate our analyzer limb at the angle of 135 right here and measure it. Okay. The second step is done. What's next? The next step is the third step. We should measure the intensity of right and left circulated components here. Just, you should know that for the first measurement here, the angle, the azimuth of this polarizer is zero. In order to future, in order to measure the whole millimetrics on the next, we should here in, if I know, or set zero degree, 45, 90 and right circulation and do for each of this orientation, do all these measurements. How much, how many? One, two, three, four, five, six. So the whole number of measurements will be here six and here zero, 45, 90, right circulation. 24. Yeah. 24 measurements in order to get the whole information about the optical properties of this sample. So let's do the third step. In third quarter wave plate, eight. Yeah. This one. This one. There. Okay. And set the transmission plane of analyzer nine at the angle of 45 degree. So firstly, we here analyzer should be oriented at 45 degree here and we insert our previously adjusted quarter wave plate because it can be at any angle. Yeah. Like it should be adjusted. And despite of polarizer and analyzer, the quarter wave plate, it's completely clear. You can't do any adjustment without this and this polarizers. In order to adjust one quarter wave plate, you should, you should use two polarizers. Okay. Let's do. This one is called, this is, this is conditioned for a right circulation. So we should find zero and rough here, but right. Yeah. And make a photo. Okay. Yeah. Yeah. Okay. The next step is the set the transmission plane of this analyzer at the angle of 135. Let's do this. I do this instead of you cause this one is not screwed to this table. So it can, but you can see all this procedure. So yeah, you're welcome. So here is the condition for a left circulation. Okay. We should find zero leave, leave a left Ukraine and add our photo. Okay. Here we are. Yeah. Exactly. Let's return to our Matlab scripts. Matlab scripts is very, this Matlab script is very simple cause here we should read our images converted in a double class and here make some simple editing and so on. And after that's a normalization. Okay. Okay. One more. We should, okay. Okay. We should download this images in the proper directory. Just a moment. Here we are. They are all here started here. Yeah. Okay. And after that, we should run our, oops, what's the problem? 045 or maybe, maybe, maybe, maybe, so this one is work. Yeah. Yeah. This works. But what about this one? Oh, excuse me. Okay. But what happened with this one? Okay. Okay. We are not used this. This one is not necessary. Oops. Oops. Okay. It should work now. Yeah. So some part of program for the whole millimeters calculation and just now we don't, we don't, we don't have those. So here we can see the four stocks vector parameter. The first one, it's a normalized it completely unity cause it is a whole intensity. Yeah. It's a components, sum of components of zero degree and 90 degree. The second one, it's a prevailing of zero degree intensity or zero degree, degree polarization. It's a difference. Yeah. On the 90 degree, the third one here. Yes. It's a prevailing of intensity of polarization component on 45 degree on the 135 degree. And the fourth one, it's a prevailing of right circulation on the left circulation. This is the whole stocks vector. This is the field parameters. So now we can deal with the field. So if we use the same statistical moments and the results, yeah, we can obtain some, some parameters. It can be used and they are, they are using in order to discriminate between of different groups of samples. For example, as it, as it was said, the third one and the fourth one parameters here, you can see regarding for example, to the previous results here. It's 11. Yeah. Cause the, the mean value is, you can see it 0.01 standard deviation is 1.3. The dispersion is a square of standard deviation skewness is quite small, but the kurtosis is quite big. And this wide range of changes of these skewness and kurtosis statistical moments can be as a tool for discriminating between of different samples in, in, in, in a different groups. So in order to save time, you don't do the same measurements for different angle of this polarizer. I just show you the results of already measured samples. Okay. So you can see one moment here. For example, but here there are different samples. My cardamom tissue, we have already now. What about blood plasma, right blood plasma, the droplet of blood plasma on the, this glass and dried at room temperature for a, for a, for a one day, for a 24 hours. Yeah. Pretty nice samples. You can see it here. This is the morphology of such a samples. And for example, if we use this one here, you can see a 24 measured images. We should, we should download it in our destination directory. And I hope without problems, we can obtain now, we can calculate the whole builder matrix of our sample. Hope, I hope. Let's check fix sometimes. Yeah. Here we are, but a little bit large, this photo. Here you can see the 16 elements of the whole Mueller matrix of this sample. This, not this, but for a plasma sample. As I, as I said, so you can see it that this matrix has a diagonal structure. Yeah. These elements are prevailing on these elements. So some processes of polarization depolarization exists here. The most promising due to the diagnostics and so on. You can remember it's a Miller matrix invariance. It's a f44. This one is connected with a linear bifringence of our samples and the combination of these two diagonal elements with these two. Also, this one, one, one, four. Yeah. And for one, it's correspond to the linear dichroism and linear and circular dichroism. So you can use the tools of statistics analysis to analyze each of these elements, but you should know some few words about the morphology of your sample. What changes are in, in this morphology exist due to different diseases. For example, if we have a skin cancer, if this can be a skin, yeah, the upper inner inner upper layer of skin, what, what, what is physical mechanisms are in during this cancer changes? For example, increase increase in circular bifringence. Okay. If you should know it from the medical point, from biological point of view. Okay. Yuri, I think we should send the first group, group number four for MLAP. So this is, this is it. Thank you. Yes. Yes. Yes. No, no, please, please, you can sit here. You can, you can come 10 minutes before three, 10 minutes before three, you can follow to MLAP. Now we have time. Yes. Sorry. But group number five is invited to see closer experiments and anybody else. Okay. So thank you for questions. Okay. As you shared a little bit later, maybe, maybe, maybe you have some questions about, oh, please, please, please, please be my guest. So just once more. Laser beam, yeah? Just more advance for your group. It can be any type of laser firstly, but for different wavelengths, some problems can be in the choosing of exact water wave plates because water wave plates is more precise for only for one chosen wavelength. It can, it can, it fabricated. But this one, these two, these two are aromatic. They are working within whole visible range. So in, in this case, you shouldn't be worried about some, some, some distortion or something like that. The second important thing, the, it's a strain free microscopic objective here, this one. It's a, it's a Nikon, Nikon infinity corrected objective is a magnification of four here. Four, yeah, four. Because it's a, it's a, it's a long distance in the, this long small, uh, magnificated objective are preferable for, for this demonstration. For example, you can, you can, uh, such a polarimeter on the base of polarization microscope. The only problem that in polarization microscope, uh, we have this limp analyzing limp in polarization microscope as for me, mostly, uh, beginning from zero and, and to 90 degree. So the angle values of 135 degree cannot be measured in, in the, in this case. So you should, you should renovate it. Yeah. And, uh, this quarter wave plate exists in polarization microscope in analyzing unit, but this is missing. But you can, this plate is no problem. You can, you can just put it on the, after the illuminator on the polarizer and so on. So it is not, but, what is this limp? But I, I don't know what about with the most modern, for example, Nikon multifunctional microscopes. It's about costs, uh, more than, more than 100,000. Yeah. So maybe, maybe, maybe there, but in, in most inconvenient polarization microscope, such angles are missing. Yeah. This one. Also, the angular aperture of this microscopic objective should coincide with the, uh, radiation, diagram of your sample in order to avoid filtering. Yeah. Such thing. Some, some, some, some, some calcium I need. Yeah. Yeah. Thanks. Cause when we have, when we have a sample, yeah, which is irradiated here, every sample has some diagram of scattering. Yeah. Yeah. This one can, can be this one and so on. And your aperture of your numerical aperture of your objective should collect all these frequencies. Cause when we have this situation, you shouldn't have information about this frequency, only this one. And this one frequencies correspond to, for example, it's like a, it's, it's called special frequency filtration. So you should, you should avoid this. So you should firstly, for example, if you deals with the, samples, for example, of one group or one type, for example, histological sections, something like that, you should measure the, this indicator tricks of scattering. And due to this choose the appropriate objective. So in order to, to, to get more precise results. So, what, what, what else, what else, what, what questions? Yeah. Good. A little bit louder. Come, come here. Yeah. Come here. Yeah. Actually you recorded the saturated images. Why? Because there are some maximum intensity, maximum intensity is I think 255. Here you can see. What do I mean? Saturated? Yeah. These are not saturated. No, this is, this is exactly image. Okay. What is dynamic range of this? It is 8 bit or 12 bit? It is 12 bit. I think. No, it is not 12 bit. It is 9 bit. 8 bit. Yeah. 8 bit. Yeah. So maximum is 255. Here. Yes. Exact question. So this is only the demonstration, but in the real case, you should use camera with appropriate dynamic range in order to this illumination. Because this laser, it's quite, it's quite strong. So, and you can some saturation because, yeah, it's, it, they saw, but in polarimetic measurements, the situation is prohibited. You should use only linear regime of the CCD camera. What, what, what is, what is the overcome of this? How we can overcome? We can use the neutral filter there. Yeah. Exactly. Exactly. And what about if the sample is a resemic mixture of right circularly polarized and left circularly polarized, then how can we differentiate between these things? About left and right circle? It is a resemic mixture. No. The left circular polarized and right circularly polarized, it can be filled. It's filled, filled after the sample. Yes. Because the sample, yeah, here, you can see it. When we, we are going with the one moment, when we are going with the stocks vector parameters here, it's the right question. Yeah. Here. You can just analyze, let's analyze this force stocks vector element. You can see it? Yeah. So, yes, in this field, in strongly, this biological objects are strongly active object. They create optical inhomogeneous polarization in homogeneous field. And this, in homogeneity, you can see it here from the, the field consists of right circulated and left circulated. How we can separate between of them? Because the, as you can remember, because the zero one, it's a linearly polarized. We can use only the extraction. Yeah. So minus one towards left. Left. Yeah. Plus one is, yeah. And zero, it's a linearly polarized. Yes. This, this one, yeah. Does it take care of Malus law inside? Sure. Malus? Yeah. Yeah, exactly. Exactly. Because Malus law is, it's just, it's, yeah, yeah. It is, it's just, so it's a, yeah. It's a, for a pure polarizer, you can, when you rotate it due to the, due to the angle, yeah. So in the intensity. And you're talking about kurtosis. So what property of sample you're extracting using kurtosis here? It should be, it should be analyzed a bit before of that. For example, I, using kurtosis here, you can analyze this distribution. For example, for one sample, for a normal sample, the kurtosis, for example, there are only mostly right circular polarized field. So it is with right circular and left circular. So yeah, yeah. It is kurt. Yeah. And how wide is this modulation of polarization? The kurtosis can, can, can say about us, about, about this. And, and what is, the skewness is about the same. Yeah. The same. Because it's a self-constituent parameters. So you can use only mean, for example, or only standard deviation, but, or only skewness, or only kurtosis, but better to use them all in a group in, in so. So basically, both kurtosis and skewness, you are measuring for right circular polarization and left circular polarization. Yeah. Yeah. Yeah. Thank you for your question. Right? Maybe, maybe. Yeah. What's the discussion? Yeah. What about? You want to see? You want to see. Okay. Here, for, for the first time, in order to measure the stocks vector, yes? So firstly, you should have some soft, it can be even, and I don't know, some, something like drain systems or something like, in order to get virtual dub. Yeah. And something like that. In order to connect the CCD camera to your computer and to get, you get an image from, from this camera, yes? Okay. And after that, it is your, your, your, your curiosity. So for the first time, you should put here zero degree. Yeah. This one, yeah, zero degree. It's a, you can find it in, in this one. Advises. Yeah. So in order to measure the stocks vector parameter, parameters. Here you can see a polarizer. This, this one polarizer is not really scientific. Yeah. You know, what is it? It's a CPL for a DSLR camera. So yeah, I can see it. It's not, not very, not, it's a, it's a, yeah, it's a, there are very many of this one. Yeah. This one is the same. But the quarter wave plates was made on our demands in order to cover whole range of visible, of visible light from four, four hundred and forty to six hundred and fifty from blue, from blue to red one. Right now, right now the here, here is a zero. Let it be this one. Cause in order is, is, you know, these measurements are depending on one of the other. What is the really polarization from here? I don't know. Cause it, it, it can be defined using the Michael. Yeah. You should use this. Oh, yes. I have remembered. They have used the Brewster angle and rotate polarizer through the vanishing of illumination at the Brewster angle. And we should know that in this condition the polarization is right here, right here. But, but this is, this is important actually if you want to, to know what is polarization right here. This is linear. But all measurements we do in, in corresponding of this polarization. So if it is necessary to know that you should, you want that polarization of illuminating beam should be okay, please. But the matter of fact that if we have the here zero, here we make 90 degree and a vanishing of decreasing of minimum signal. Okay. We know that this one and this one is crossed. Okay. So, and after that we adjust this quarter wave plate in order to this crossed polarizer and analyzer and this one. So, and then the polarimeter setup is adjusted. If you want that, if it is important that polarization, for example, when here is zero. Yeah. This is unsolved creature. This one is only with a limb. So, but if you want to hear this one, you can adjust with the Brewster angle. This polarization right here. So this is, this is your choice. And for example, this one, this is a semiconductor laser here. Yeah. It's a no, no, no. Okay. Yeah, yeah, yeah. No, yeah. So, yes, laser beam is, is unseen in this direction. Yeah, yeah. It's a, it's a, it's a simple laser in order to cause what, what is important else? The stability of laser radiation. Because the stability is a, for example, intensity of laser radiation against to or versus time would be this one. For example, for this type of lasers, it's a, can a little bit, a little deviation can be, can exist. But this deviation is not prohibited for polarimetric measurement. You should get, you should, you should use stable. Yeah. So on the rest, you, I think, yeah. Okay, Viktor. So please, group number four, you can join MLAP now is ready for experiment. So group number four can go to the MLAP. If group number five already listened this experimental part, so you can also join. If you was here, you can also join MLAP. Okay. And all the rest I invited to, to look, try, maybe some ideas. Someone has additional questions. You're welcome. Guys, what about you? Come closer. Let's see this one. Come everybody because we have not too much people. Yeah. Yeah. This one all the rest probably in the city center. Can minimize to the, to the construction limits. So also this is a laser here. This is polarization state generator. Consist of polarizer and quarter wave plate here. Quarter wave plate on one type of measurement is inserted on the other type measurement. Uninserted. Yeah, take off. So with the help of these two optical devices, polarizer and so-called optical compensator, you can produce all type of polarization beginning from right circular linear to the left circular. Yeah. Do you know Poincare sphere? Yeah. It's something like that. Here is a linear states here. Right circular here. Left circular. What about here? Elliptical. Super. And even elliptical polarization, you can cover with this device, with coupling of these two devices. You can cover all the Poincare sphere. So if you want. The second one is a imaging system here. Consist of objective in, in the most simplest case, objective, but objective should be strain free in order not to create from, for example, linear polarization, something like thin ellipse. Yeah. This is an object. So you hear about the coincides of the indicators of scattering of this sample with the aperture of this objective. So the image forms in the plane of the sensitive, light sensitive plane of this CCD camera. CCD camera, as it was said, should be linear. We should always avoid the any distortion and saturation in this plane. So, because even if you have, for example, if you want to, as it was said in previous lectures, if you want to create low cost device, yeah, you can use the simplest CCD camera, not very, for example, with this, with this linearity characteristics, for example, something like that. So you can use the neural density filter in order to decrease the power of your laser and work in this linear range. So it's no problem. No problem. Due to the laser, it can be a laser. It can be, for example, a xenon lamp. And after the xenon lamp, you can use, you can set up different type of filters. For example, it can be like convention filters. And it can be, for example, if you want to have narrow band in your wavelengths, it can be narrow band interference filters. It's more, for example, it's more expensive, but for different tasks, if you want. For example, if you know that in this sample, the most absorbing components are, I don't know, some proteins, for example, or amino acids, you can use very specific wavelengths in order to see the maximum contrast of your image here. Okay. Here is a polarization state analyzer. It's the same like, just like that, but inverted. This quarter wave plate can be adjusted or go out from the beam, laser beam. And with this PSA, position state analyzer, we can analyze field scattered by this sample. Yeah. And this is also universal, because you can analyze any fields you want, even partly polarized or unpolarized. Because you know that the stocks vector for a completely unpolarized light, the following, because only intensity plays a role. If you have a partly, you should, here you have some values, yeah? But this one, S0, will be bigger than the sum of this S1, S2, S3. It's a partly polarized light, or partly coherent light. For a purely polarized light or coherent light, it's equal. Yes. So, and the next step is a calculation of stocks parameters. You have seen it, calculation of Miller matrix elements. And this is only a half part of your work. Other part of your work, you should decode these images, so that a Miller matrix or stocks vector imaging, bio-imaging also, yeah, like our college code. So, and the next step, you should analyze, you should go deeply inside the morphology of your samples. What are the main structures here? What kind of amino acids here can be, what kind of proteins here, protein structure, can be LST, in museum, both of them, and so on. Morphology, yeah. So, and knowing, having knowledge about morphology, you, after that, you should analyze how these former elements of constituents of these samples, of the sample or samples, in the living tissue or in this one, ex vivo measurements, how it changes. Due to the, for example, for due to the disease, you are investigating. And only after that, knowing these mechanisms and what kind of changes they produced, diseases mechanism and what kind of changes they produced in the structure and morphology of your sample. You can decode your, for example, you can choose one or several of these Miller matrix images or stocks vector images, for example, and analyze it more precisely, more, for example, with the help, we are talking about the correlation approach, more sensitive to the, than the, for example, for different tasks than statistic fractal approach and so on. Wavelet approach, if you want, because Wavelet gives you information about different, different structures with different frequencies and with different sizes. It's like a mathematical microscope. And so on, Fourier analysis of these images, so on. But you should know before that morphology and what kind of changes are there and so on. Okay. But the next, the next step. Okay. In order how, how you can measure this, this four parameters, it's like, like here. So this one, yeah, first three steps. These three steps allow you to measure, yeah. But in order to, to get the whole Miller matrix, maybe, you know, yeah, this is mechanisms. So you should, this one, what we, what, what we did, we measure only one stocks vector with four parameters. You should measure at least four. Four. The illumination condition here is linear with zero degree, azimuth linear with 45 degree. Yeah, we can, we can, for example, okay, 45 degree. Yeah. And we should continue this procedure once more. The next one, 90 degree and once more. And then right circulation. Yeah. And, and this is, this, this images, all your measure, you will measure gives you the possibility to calculate all this one. Yes. M I K or my G here. This is a, here it's a stocks vector elements in my club. It's very not complicated. It's, it's just, it just, it just the arithmetic's not even not, not algebra. Yes. Yes. Yes. Here it seemed information. Yeah. So this, this object, yeah, the right question. But there are very many setups. For example, what conventional polarimeter doesn't have the image formation unit. It's only a beam, for example, different directly from a laser, directly to the city camera. And for example, here, some convex convention, conventional flows or some turbulence and so on and so on, or some material can be, and we also can measure, but without formation of image. Why the image formation is example. Okay. It's important for us because we want to know information about morphology structure. Here you can see it. You can see different. For example, this is not really image. This is calculated image, but the image you can see here. Okay. For example, what my cardam, cardam tissue is pronounced. Not really. No. Here you can see morphology. Yes. This collagen fibers, collagen and myosin fibers. You can see it. Even looking, for example, for a proper histological section or X vivo or in vivo, you can set that, for example, there are no disorders. There are no some, for example, some changes. You can see it by, by your eye. Yeah, exactly. Because this is coordinate distributions. Yeah. So it's just, it can be translated like when we took the first and first pixel of the city camera. This is a conventional polarimeter in one point. But we should know, we want to know the coordinate distribution of these parameters, stock vector parameters, Miller matrix parameters. Of course, every point of in coordinate distribution of Miller matrix correspond to the point of this image, the corresponding point. Exactly. Even in our lab, it can be done by means of using the, you know, matrix printers, matrix printer, Epson, this step engines can be used, can, yes, can be used step engine, not, not point by point, but step engine about the, this typer when they, they moving. Yeah. Because even in our lab, my colleagues here, they produce this device in order to this two computer controlled analyzer and polarizer. Yeah. And it is possible. And the time of one measurement, for example, here, if you really good experienced in rotating and so on and clicking here. So it, it, it can be, three to five minutes. It can be done one, but with the help of step engine or something like less than one minute per sample. So even faster, I don't know. There are very many polarimeters exists because this one is a conventional and the most, it's, it is, it is most understandable what, what are going on with this polarization light. There are type of, type of snapshot polarimeters when by one measurement, by clicking one time, we measure all four stocks per meters simultaneously. There are, but the accuracy of such measurements is a little bit less than here. Because there are some calculation and so on and four year transform and where's and so on. There are several types of polarimeters with a pockel cell with a liquid crystal cells instead of rotating polarizer and instead of quarter wave planes. So you can use a liquid crystal cells with different, with different voltages applying different voltage. You can different phase difference. Yeah. Yeah, exactly. Special light modulators. So, but the reason, the nature of this here, so polarization plane, optical compensator and all the processes, this one, yes. But if, if, if we use, for example, no, no, no. If we use a Honeometric scheme, yeah, this one is not, not moving. And this one, this is also not moving. And this one can be rotated from zero degree to, to here. No problem. Don't do this. Okay. Okay guys, thanks a lot for the questions. Yeah, you are welcome. We have two days, two days left.