Thank you for this video. I am trying to follow this step. But at minute 6:20. what is the value for Relative Permittivity and why appear sign STOP at Electrical Conductivity? Can you share how to simulate multimode taper fiber sensor for absorbance?
The relative permittivity is equal to 10.8. The electrical conductivity value is not mandatory for this setup and the software ignores it. I will record a video for it at the future.
Your tutorials are a gem, especially to someone like me who recently started learning on Comsol ! I really appreciate the fact that you took the time to put this content out there for everyone. I have a small inquiry, if you don't mind of course. I have been trying to simulate the photo-induced force microscopy on Comsol, which is basically an AFM system that is equipped with a QCL Mid-IR laser illuminating the tip-sample junction at 45 degrees. One of the things that I am mightily struggling with is knowing which EM wave function to use to simulate this QCL IR-laser behavior across a range of frequencies. Does the method that you followed in this "Simulation of a Metasufrace Absorber" work as well for the IR-laser ? Or is there additional functions/modules that need to be accounted for?
Thank you for your kind comment. I did not simulate QCL before in COMSOL, but I think for your case the incident EM wave should have plane wave or gaussian beam profile which both of them can be implemented by RF or Wave Optics module.
@@EMSpectrumLab Moreover, did I need to set the wave equation of the air domain? In a practice case, I didn't set the wave equation of the air domain, and the electric field disappeared in the air domain.
@@nnndaniel9705 Yes, you did, but the "Wave Equation 1" is set for the electric field calculation in "Air" & "SiC" domains by using the refractive index as default.
Thnaks you very much for the tutorial. I have questions about some parameters in Wave Equation setting. Do the [Oscillator strength] and [Damping in time] always be 1 and 10.5e13 respectively? The metal I use in simulation is Aluminium by the way.
If you use Drude model, "Oscillator strength" should be 1 (where is "fj" parameter in the defined COMSOL equation). But "Damping in time" parameter is related to your metal characteristics. For this purpose you can find this online reference: www.wave-scattering.com/drudefit.html
Can you provide any reference textbook or material to understand what happens behind the software analysis. How the analysis being carried out using FEA.
Thanks for this video. This is very helpful. I have some problems regarding the metamaterial absorber. At 9.59 minutes you said that the incident wave has TE mode. What change should be made in the model if the incident wave has TM mode?
Amazing tutorial. I have one question though. As we see here there is two peaks in the absorbance graph meaning two wavelengths get absorbed the most, what if I want a metasurface that absorbs three wavelengths, for three peaks in the absorbance graph? what changes should be made? Thank you in advance :)
Thanks for your comment. For this purpose you should sweep the dimensions of resonators over frequency to reach the optimum dimensions for three resonances in the absorbance spectrum.
@@EMSpectrumLab Thanks for the reply :D Unfortunately, I am not at all experienced in COMSOL, so I do not know how to sweep the dimensions of the resonators. Can you please explain how to do that or show me somewhere I can learn to do that or tell me a mathematical way to find the dimensions?
@@zohaibnadeem9385 You can add "Parameter Sweep" in study & select your desired dimensional parameter to perform sweep similar to what I did in the video for frequency sweep.
Failed to find a solution. The relative error (0.14) is greater than the relative tolerance. There was a warning message from the linear solver. Iterative refinement triggered. Returned solution is not converged. Not all parameter steps returned. I got this when I simulate the code. how to solve this problem? thank you
Thank you very much, this video was very helpful. Just a question the absorption is A(ω) = 1 - | S11 |^2 - |S21|^2 , the reflectance S11 and the transmission S21 . How can you calculate the transmission in ewm module of comsol? It does not respond to abs(S21)^2 command. Thank you
Thanks for your kind comment. For this purpose, you should add an air area bottom of your unit cell (like port 1) and define another port (port 2) for calculating transmitted wave same as what I did for port 1 (note that for this port you should set excitation off). After running simulation you can find S21 result.
Very helpful. Can you explain how to set circularly polarized (RCP or LCP) as an incident wave. In COMSOL there is no direct way to set CP except 1D/2D Axis symmetric space dimension. I tried by setting Background field as (Eb: x=0, y=exp(-j*emw.k0*x), z=j*exp(-j*emw.k0*x)), however the obtained result with this setting and with linear polarization are identical. Because of identical results, I think the setting for circular polarization have some problem. I will greatly appreciate any explanation/suggestion regarding this problem.
Your expressions for the circular polarized wave in COMSOL is correct, but you should enter these expressions in "Port Setting" of your physics module as electric field value.
@@EMSpectrumLab Thank you for your response, this works very well. In addition, if we want to change the polarization like RCP-LCP or LCP-RCP, then the equation (Eb: x=0, y=exp(-j*emw.k0*x), z=j*exp(-j*emw.k0*x)), only changes negative sign into positive and vice versa like this (Eb: x=0, y=exp(+j*emw.k0*x), z=j*exp(+j*emw.k0*x)). Is this correct for polarization conversion or we will need to do more in setting?
I want to separately check the amplitude and phase values for co- & cross-polarization. e.g, RCP - RCP (co) and RCP -LCP(cross). But like CST, here in COMSOL I am unable to simultaneously excite more than one mode, therefore couldn't understand how to achieve cross-polarization. Can you please explain how to achieve cross-polarized reflection/transmission in COMSOL.
@@EMSpectrumLab I want to change the phase to make an EH field animation. Do you know how to do it? I guess to use evaluation group to product phasor make it easy but it dragged me. I dont know how to deal it. Hope u can help me. thanks a lot
Sir, thanks for your tutorial~ I'm now also working on metasurface absorber, your tutorial really helps me a lot. I have a question, if it is a single antenna, why should I use periodic port? Besides, if I want to calculate transmission, how do I set the periodic reference points? Thank you very much in advance.
It is a periodic structure in both x & y-axes, so you should use periodic or user-defined port. You do not need to set the periodic reference points, they are set automatically by COMSOL.
Very good video, but I have a problem with displaying the result, after the second recalculation of Stady in the Absorbance section, I get a lot of parameters, could you tell me how to make it so that the original version remains there?
Thanks for your comment. To show the considered result you can select the related solution in the certain result tab. For each study after running simulation, one or more solution is created. For more information you send me your file by email.
@@EMSpectrumLab Thanks for the answer, I sent the project and the question to the mail indicated on the channel, I will be grateful if you can tell me about this problem
The material of the patch and ground plane is gold, but it is defined as the Drude model. For this reason, it can not be defined same as other simple materials like Air or SiC, it should be added as a separate "Wave Equation" to define the Drude model.
Nice Video solve my Problem, but there is still a problem . Please guide me how can i get variation in the graph by changing angle although i change angle but there is no variation in graph please guide about this
You should change alpha_1 (Theta) or alpha_2 (Phi) as the incident angles in the "Port" section. It is similar to what I explained in the video. Please watch the video again, If you don't find the solution, send your problem with details by email. emw.eng@gmail.com.
Ya ,I have subscribed already . I am waiting for new videos . Please upload the above related model . It could be very useful for my research purposes. Thank you once again
I tried doing the simulation of 1D silver grating-coupled SPP followed by these steps but encountered some problems. Could you please give me some advice?
@@yu-yu-sushi In EM simulation, Air layer thickness should be at least lambda/2. However, there is not an specific value for PML layer thickness, so to determine optimum thickness you should start the simulation with an initial value (for example 0.1*lambda) and increase it step by step. When your results remain unchanged, the entered value of PML thickness is its optimum value.
Yes, I will work on it. If you have any reference such as a research paper (with clear data) I would be grateful to share it with me. emwaves.eng@gmail.com
Thank you very much, this video was very helpful. Currently I'm struggling with the simulation of a triangular (hexagonal) lattice, I have to plot the extinction map for a sweep over incidence angle and wavelength, could you give me any piece of advice?
Very helpful video！ Thank you so much！ I've just got a job to simulate a frequency selective surface, could you give me any tips on how to obtain material parameters?
Thank you for your reply. I also wanted to reproduce the project of an article where some material parameters are missing, causing my simulation results to be biased. Now I have selected a suitable set of parameters in the material library built in the software: )
Good videdo sir. I have a doubt sir how to plot permitivity; refractive index and permeability from s parameter value getting from comsol. Can you do a video on that?
I don't know the direct method to calculate these parameters from COMSOL. However, you can use this reference to compute the electromagnetic parameters by S-parameters: journals.aps.org/pre/abstract/10.1103/PhysRevE.71.036617
Hi, very nice video!! This was really helpful since I got some troubles on simulating these type of metasurfaces. I also have some problems on modeling sphere dimmers. Maybe you can give me some recommendations/tips.
@@EMSpectrumLab Yes, I'm already a subscriber!! So, I already did the example of scattering by a single particle that COMSOL offers but when I tried the dimmer configuration, something is wrong. It seem that the results in the C_abs is like there was only one particle, so I think my mistake/question is how to calculate the C_abs and C_scatt.
@@miguelgarcia2133 Thank you for subscribing🌹 If you mean this example: www.comsol.nl/model/scatterer-on-substrate-14699 , when I see its file, the structure is periodic, so this example should be helpful for you. As far as I know, C_abs or C_scatt must be computed as the method of this example.
@@EMSpectrumLab problem is that when i change angle if incident there is no variation in the graph. I change only angle from parameters is this is write method or there is an other parameters rather than angle of incident to change for variation in graph please guide me
@@qamarjutt8485 When you change incident angle parameter in "Parameters" section, your results should be changed if the incident angle parameter is set in the "Port" setting as incident angle.
Thank you for this video. I am trying to follow this step. But at minute 6:20. what is the value for Relative Permittivity and why appear sign STOP at Electrical Conductivity? Can you share how to simulate multimode taper fiber sensor for absorbance?
The relative permittivity is equal to 10.8. The electrical conductivity value is not mandatory for this setup and the software ignores it. I will record a video for it at the future.
Your tutorials are a gem, especially to someone like me who recently started learning on Comsol ! I really appreciate the fact that you took the time to put this content out there for everyone.
I have a small inquiry, if you don't mind of course. I have been trying to simulate the photo-induced force microscopy on Comsol, which is basically an AFM system that is equipped with a QCL Mid-IR laser illuminating the tip-sample junction at 45 degrees.
One of the things that I am mightily struggling with is knowing which EM wave function to use to simulate this QCL IR-laser behavior across a range of frequencies.
Does the method that you followed in this "Simulation of a Metasufrace Absorber" work as well for the IR-laser ? Or is there additional functions/modules that need to be accounted for?
Thank you for your kind comment. I did not simulate QCL before in COMSOL, but I think for your case the incident EM wave should have plane wave or gaussian beam profile which both of them can be implemented by RF or Wave Optics module.
Thank you for this video! I am trying to follow this step. But at minute 11:40, why is the Number of values set as "151"?
It is the number of values of lambda interval to calculate the related graph. It is a arbitrary value.
understand. Thanks!
@@EMSpectrumLab Moreover, did I need to set the wave equation of the air domain? In a practice case, I didn't set the wave equation of the air domain, and the electric field disappeared in the air domain.
@@nnndaniel9705 Yes, you did, but the "Wave Equation 1" is set for the electric field calculation in "Air" & "SiC" domains by using the refractive index as default.
Thnaks you very much for the tutorial.
I have questions about some parameters in Wave Equation setting.
Do the [Oscillator strength] and [Damping in time] always be 1 and 10.5e13 respectively? The metal I use in simulation is Aluminium by the way.
If you use Drude model, "Oscillator strength" should be 1 (where is "fj" parameter in the defined COMSOL equation). But "Damping in time" parameter is related to your metal characteristics. For this purpose you can find this online reference: www.wave-scattering.com/drudefit.html
@@EMSpectrumLab Thank you !
Can you provide any reference textbook or material to understand what happens behind the software analysis. How the analysis being carried out using FEA.
I have learned a lot from this video. Amazing!
Thanks for your kind comment🌹
Can you please guide me about video
can you include the schematics of the 1st picture how to distribute the L-shape metasurface absorber please
I can not calculate the Abosrbance according to your simulation model. Can you please help?
Thanks for this video. This is very helpful.
I have some problems regarding the metamaterial absorber. At 9.59 minutes you said that the incident wave has TE mode. What change should be made in the model if the incident wave has TM mode?
For TM mode you should set E-filed amplitude as: Ex=1, Ey=0 & Ez=0 in the port setting.
Sir not able to run scattering boundary condition. What to do?
In my simulation result scattering boundary condition is not showing.
Please help
Scattering boundary condition can be found only in boundary condition category not results section.
@@EMSpectrumLab sir can I get your email id, I need to show you my results.please
@@chaudharypiyush3559 emwaves.eng@gmail.com
can you simulate accoustic to sandwich panel ?
Hello, plz let me know what should i do for multi layer absorber modelling like at a time five layer will have in a design
For any periodic structure with arbitrary number of layer the simulation setup is the same as I explained in this video.
Thanks, dear, At last, my problems are solved watching this video on how to plot a 2D color map
I am so glad this can help you. I would be grateful If you subscribe to my channel and stay connected with me😉
Are you working on metasurfaces?
@@EMSpectrumLab can you teach me how to use comsol for plasmonic and metamaterials?
@@mustansarhussain5033 I'm working on new videos in this topic. They will be published in the near future.
Nanoslit-microcavity-based narrow band absorber for sensing applications
Xiaoyuan Lu, Lingxuan.... What video should I follow for this simulation ?
It is an metal-insulator-metal waveguide. I will record a video about it as soon as possible.
@@EMSpectrumLab Did you recorded this video or not
@@qamarjutt8485 No, I did not, I am working on other topics nowadays.
Hello, how can I design the equivalent circuit from any structure of metamaterial absorber? any source?
You can use different research papers which published in this topic. I do not know certain reference.
Have you found any source?
Amazing tutorial. I have one question though. As we see here there is two peaks in the absorbance graph meaning two wavelengths get absorbed the most, what if I want a metasurface that absorbs three wavelengths, for three peaks in the absorbance graph? what changes should be made? Thank you in advance :)
Thanks for your comment. For this purpose you should sweep the dimensions of resonators over frequency to reach the optimum dimensions for three resonances in the absorbance spectrum.
@@EMSpectrumLab Thanks for the reply :D Unfortunately, I am not at all experienced in COMSOL, so I do not know how to sweep the dimensions of the resonators. Can you please explain how to do that or show me somewhere I can learn to do that or tell me a mathematical way to find the dimensions?
@@zohaibnadeem9385 You can add "Parameter Sweep" in study & select your desired dimensional parameter to perform sweep similar to what I did in the video for frequency sweep.
Can you please tell how much time it took to simulate
Failed to find a solution.
The relative error (0.14) is greater than the relative tolerance.
There was a warning message from the linear solver.
Iterative refinement triggered.
Returned solution is not converged.
Not all parameter steps returned.
I got this when I simulate the code. how to solve this problem? thank you
Change the solution from Iterative to Direct solution in Study steps.
Thank you very much, this video was very helpful. Just a question the absorption is A(ω) = 1 - | S11 |^2 - |S21|^2 , the reflectance S11 and the transmission S21 . How can you calculate the transmission in ewm module of comsol? It does not respond to abs(S21)^2 command. Thank you
Thanks for your kind comment. For this purpose, you should add an air area bottom of your unit cell (like port 1) and define another port (port 2) for calculating transmitted wave same as what I did for port 1 (note that for this port you should set excitation off). After running simulation you can find S21 result.
@@EMSpectrumLab thank you very much!!
Very helpful. Can you explain how to set circularly polarized (RCP or LCP) as an incident wave. In COMSOL there is no direct way to set CP except 1D/2D Axis symmetric space dimension. I tried by setting Background field as (Eb: x=0, y=exp(-j*emw.k0*x), z=j*exp(-j*emw.k0*x)), however the obtained result with this setting and with linear polarization are identical. Because of identical results, I think the setting for circular polarization have some problem. I will greatly appreciate any explanation/suggestion regarding this problem.
Your expressions for the circular polarized wave in COMSOL is correct, but you should enter these expressions in "Port Setting" of your physics module as electric field value.
@@EMSpectrumLab Thank you for your response, this works very well. In addition, if we want to change the polarization like RCP-LCP or LCP-RCP, then the equation (Eb: x=0, y=exp(-j*emw.k0*x), z=j*exp(-j*emw.k0*x)), only changes negative sign into positive and vice versa like this (Eb: x=0, y=exp(+j*emw.k0*x), z=j*exp(+j*emw.k0*x)). Is this correct for polarization conversion or we will need to do more in setting?
@@faizanfaraz2376 Yes, it is correct.
@@EMSpectrumLab Thanks a lot for your response
I want to separately check the amplitude and phase values for co- & cross-polarization. e.g, RCP - RCP (co) and RCP -LCP(cross). But like CST, here in COMSOL I am unable to simultaneously excite more than one mode, therefore couldn't understand how to achieve cross-polarization. Can you please explain how to achieve cross-polarized reflection/transmission in COMSOL.
Good video!! Can I sweep parameter without lam to save time of reconstruction model and plot the same table surface?
Yes, you should set Air and PML layers thickness based on "lam_max" (maximum simulated wavelength) value instead of "lam".
@@EMSpectrumLab I want to change the phase to make an EH field animation. Do you know how to do it? I guess to use evaluation group to product phasor make it easy but it dragged me. I dont know how to deal it. Hope u can help me. thanks a lot
Sir, thanks for your tutorial~ I'm now also working on metasurface absorber, your tutorial really helps me a lot. I have a question, if it is a single antenna, why should I use periodic port? Besides, if I want to calculate transmission, how do I set the periodic reference points? Thank you very much in advance.
It is a periodic structure in both x & y-axes, so you should use periodic or user-defined port. You do not need to set the periodic reference points, they are set automatically by COMSOL.
@@EMSpectrumLab thank you very much!
Really good tutorial
Thank you, Sir, sir If we want to incident TM polarization wave then which parameter we have to change?
For TM polarization you should set E-field components amplitude as Ex=1, Ey=0, Ez=0 in port mode setting.
Very good video, but I have a problem with displaying the result, after the second recalculation of Stady in the Absorbance section, I get a lot of parameters, could you tell me how to make it so that the original version remains there?
Thanks for your comment. To show the considered result you can select the related solution in the certain result tab. For each study after running simulation, one or more solution is created. For more information you send me your file by email.
@@EMSpectrumLab Thanks for the answer, I sent the project and the question to the mail indicated on the channel, I will be grateful if you can tell me about this problem
Sir
Could you please make some videos on metamaterial absorption
What kind video do you mean exactly?
There is a point that I don't understand, why the material of the patch and the bottom is not gold, but air？
The material of the patch and ground plane is gold, but it is defined as the Drude model. For this reason, it can not be defined same as other simple materials like Air or SiC, it should be added as a separate "Wave Equation" to define the Drude model.
Nice Video solve my Problem, but there is still a problem . Please guide me how can i get variation in the graph by changing angle although i change angle but there is no variation in graph please guide about this
You should change alpha_1 (Theta) or alpha_2 (Phi) as the incident angles in the "Port" section. It is similar to what I explained in the video. Please watch the video again, If you don't find the solution, send your problem with details by email. emw.eng@gmail.com.
hello sir, thank you it is very help full, but i have a doubt how to make a array of cylinder metasurface any other video regarding about........
It is not so different from this simulation. I will record a video about Photonic Crystal in the future.
Thank you! This is very useful, can you please guide us how to model a metal-insulator-metal based plasmonic sensor using comsol.
I am glad that you liked my video. I try to upload a video about this topic, surely. Please subscribe to my channel and stay connected with me.
Ya ,I have subscribed already . I am waiting for new videos . Please upload the above related model . It could be very useful for my research purposes. Thank you once again
Can you please guide me about video
CAN YOU PROVIDE A SOLUTION I AM NOT GETTING PRIMARY RESULTS BUT SIMULATION IS COMPLETED WITHOUT ANY ERROR:
I replied to you on email.
Very nice video, thanks so much!
I tried doing the simulation of 1D silver grating-coupled SPP followed by these steps but encountered some problems.
Could you please give me some advice?
@@yu-yu-sushi I am glad it is helpful for you. What is your problem, exactly?
I found that the distance between port and grating will affect resonance positions.
How to know the proper value for PML/Air layer thickness?
@@yu-yu-sushi In EM simulation, Air layer thickness should be at least lambda/2. However, there is not an specific value for PML layer thickness, so to determine optimum thickness you should start the simulation with an initial value (for example 0.1*lambda) and increase it step by step. When your results remain unchanged, the entered value of PML thickness is its optimum value.
@@EMSpectrumLab
I see. Thank you so much for the advice! I would try it again.
Looking forward your new videos!
Hi can you do a tutorial for the similar design a metasurface but in case of polarizer
Yes, I will work on it. If you have any reference such as a research paper (with clear data) I would be grateful to share it with me. emwaves.eng@gmail.com
Great job, keep it up.
hello. i started working on metasurfaces, are you available for collaboration?
Thank you very much, this video was very helpful. Currently I'm struggling with the simulation of a triangular (hexagonal) lattice, I have to plot the extinction map for a sweep over incidence angle and wavelength, could you give me any piece of advice?
Glad it could help you. You can follow the steps of colormap plotting which I showed in the video.
Very helpful video！ Thank you so much！ I've just got a job to simulate a frequency selective surface, could you give me any tips on how to obtain material parameters?
Thanks for your kind comment. What is your problem exactly?
Thank you for your reply. I also wanted to reproduce the project of an article where some material parameters are missing, causing my simulation results to be biased. Now I have selected a suitable set of parameters in the material library built in the software: )
Good videdo sir. I have a doubt sir how to plot permitivity; refractive index and permeability from s parameter value getting from comsol. Can you do a video on that?
I don't know the direct method to calculate these parameters from COMSOL. However, you can use this reference to compute the electromagnetic parameters by S-parameters: journals.aps.org/pre/abstract/10.1103/PhysRevE.71.036617
Nice video. Can you please make a video on acoustic black holes ?
Thanks for your comment. I do not enough knowledge about it. But I'll study more and try to upload its video at future.
hello sir can you please make a video on multipole decompsition of metamaterials (metasurface) please sir🙏🙏
I try to record a video in the near future.
Hi, very nice video!! This was really helpful since I got some troubles on simulating these type of metasurfaces. I also have some problems on modeling sphere dimmers. Maybe you can give me some recommendations/tips.
Thank you for watching. I will be happy if you subscribe to my channel and stay connected with me. sure, what is your problem?
@@EMSpectrumLab Yes, I'm already a subscriber!! So, I already did the example of scattering by a single particle that COMSOL offers but when I tried the dimmer configuration, something is wrong. It seem that the results in the C_abs is like there was only one particle, so I think my mistake/question is how to calculate the C_abs and C_scatt.
@@miguelgarcia2133 Thank you for subscribing🌹 If you mean this example: www.comsol.nl/model/scatterer-on-substrate-14699 , when I see its file, the structure is periodic, so this example should be helpful for you. As far as I know, C_abs or C_scatt must be computed as the method of this example.
Can you please guide me about video
Your tutorial is very impressive thanks so much! can you share me the mph of your model please
You can email me: emwaves.eng@gmail.com
can u please explain it in CST? thanks
I am so busy nowadays. But I will record its video as soon as possible.
@@EMSpectrumLab thank u so much sir, looking forward to it because i am working on absorbers now and i need the help, thanks.
Sir
Can you please tell the name of the paper you reproduced
Paper link: opg.optica.org/oe/fulltext.cfm?uri=oe-23-7-8670&id=314237
Great
hello. i started working on metasurfaces, are you available for collaboration?
Thanks
Can you please help me regarding this video i have have problem
What is your problem exactly?
@@EMSpectrumLab problem is that when i change angle if incident there is no variation in the graph. I change only angle from parameters is this is write method or there is an other parameters rather than angle of incident to change for variation in graph please guide me
@@qamarjutt8485 When you change incident angle parameter in "Parameters" section, your results should be changed if the incident angle parameter is set in the "Port" setting as incident angle.
@@EMSpectrumLab sir i change but there is no variation graph can i send you file if you check it
@@qamarjutt8485 Yes, please send it to this adderess: emwaves.eng@gmail.com
hello. i started working on metasurfaces, are you available for collaboration?
Hi, I'm so happy If I can collaborate with you on the metasurfaces research area, but now I am so busy and dont have enough time.
@@EMSpectrumLab can you please try to redesign this model in CST software?
@@hamzaasifkhan8421 I will upload a video about metasurface simulation by using CST in the future.
@@EMSpectrumLab looking forward to it Sir. Thanks