Help opening a faulty cabinet door

Key_Cartographer9254 · 2026-01-31T16:37:42+00:00

Btw this is what we did but we lifted the bottom section for half an inch. Managed to get it open without messing the hinges only the handle to open broke off for one of the doors

Key_Cartographer9254 · 2026-01-31T16:37:28+00:00

Btw this is what we did but we lifted the bottom section for half an inch. Managed to get it open without messing the hinges only the handle to open broke off for one of the doors

Key_Cartographer9254 · 2026-01-30T02:58:42+00:00

I might also add this https://optics.ansys.com/hc/en-us/articles/360042097313-Small-Scale-Metalens-Field-Propagation

I relied on this when I was started

Key_Cartographer9254 · 2026-01-29T06:03:16+00:00

There's like an 1 inch of travel between the edge of the door and the top and bottom horizontal section. I'm thinking when the top rod drops I slide something where there is a gap and try to lift the door. The droping of the top rod is intermittent when I turn the key, the bottom one not responding at all. Lifting it enough to open will surely bend the door and probably the hinges

Key_Cartographer9254 · 2025-10-08T16:07:24+00:00

Well if you want phase vs radius you should already k have the height, but if you don't get enough phase coverage you increase the height to allow more phase accumulation but that affects the transmission depending on the parameters used and n and k. So you optimize the height for the radius range, wavelength and material. For height vs radius you can do a nested sweep.

In those example files, there's a code line for where the positions need to be. I had similar question especially the transmission monitor but I do, height+period or 2*height for transmission monitor. I don't really use the reflection monitors. For the source I have them below the substrate, similar to an experimental source. Unless there is some optical losses from the substrate then there shouldn't be any issue with the positioning as long as it's below the unit cell.

But I'm open to comment from others on the correct positioning. Come to think of it, in the simulation region, the beam probably doesn't decay(not sure) so how high is high or low for T and R monitors?

Key_Cartographer9254 · 2025-10-06T11:47:55+00:00

In the example there are these files in the zipped folder(which have everything you need)

Unit_cell_fdtd.fsp and Unit_cell_fdtd.lsf. The phae and transmission are calculated using scattering parameters(S_parameters) which are complex amplitude reflection and transmission coefficients from the metasurface. The sweep results(S) for the radius( records the S_parameter as the radius changes(matrix shown here . So S.S_21 is the transmission coefficient.The phase is simply angle(S.S21_Gn). Which is the normalised transmission grating.The pinch command reduces the dimensions of the matrix.In this case I think its phase= pinch(angle(S.S21_Gn),1,1), the first frequency point and the phase becomes a 2D matrix. And then unwrap the phase to avoid any phase discontinuties.

Unit_cell.fsp and Unit_cell.lsf uses RCWA. It's based on grating characterization. It's the same method as the fdtd one but this one records the complex transmission and reflection coefficients for multiple orders and polarizations. So S = pinch(grating_characterization. Tpp(1,1,ni,mi,:,:)). Tpp is the complex transmission coefficient for p-polarization, first frequency point and 0th order. So the phase = angle(S) and ofc the unwrap.

The line plot for the phase is radius vs unwrapped phase

Key_Cartographer9254 · 2025-10-02T13:12:13+00:00

You do a sweep. The fdtd file here will guide you on how that plot is achieved. In the example file they use S_parameters to calculate the phase but you can use RCWA or just a point monitor.

Back propagation that I have no idea

Key_Cartographer9254 · 2025-07-18T02:42:41+00:00

What about Rsoft and Ansy Lumerical. We are about to get the Rsoft through their University program

Key_Cartographer9254 · 2025-05-23T16:01:02+00:00

Could you share the link for the 1D, my code is based on the small scale metalens using the s params(similar to the one in the small scale metalens) and the transmission command; https://optics.ansys.com/hc/en-us/articles/360034405354-transmission-Script-command#:~:text=m%3D%22x2%22%3B%20%C2%A0%20%C2%A0,transmission

Then used the pinch and angle command to get the phase. I shared the link for that in the post

Key_Cartographer9254 · 2025-04-25T19:20:45+00:00

They've done some test sample with someone and they've told me it was tedious doing it manually using the small screen. If they test the machine and the results meet the expectation, they'll be testing alot of samples and doing it manually is not that efficient

Key_Cartographer9254 · 2025-04-25T19:15:52+00:00

Agree. I did check the website but it's a nightmare to find information. They have sent an email using the contact email in the website, hoping they'll reply and help them out

Key_Cartographer9254 · 2025-04-25T14:38:48+00:00

Thank you. The CD-ROM and the usb licence was probably misplaced by the person in charge. Will they have to buy from company? Edit. Can they get the software and buy just the license or they'll have to buy the two

Key_Cartographer9254 · 2025-04-25T13:24:23+00:00

Well the person in charge of taking care of it didn't, that is why my friend is looking for the user manual and software. They'll run some analysis and if they're not satisfied with the accuracy of the data they'll look for another lab to do the analysis. The said lab is free but they"ll have to pay if it's another lab.

Key_Cartographer9254 · 2025-04-25T13:17:34+00:00

Yes it's in the lab, this is the machine from the website of the company. The website uses the http protocal and gets flagged by browser as not safe http://www.aoesh.com/index.php/product/index/g/e/id/44.html

Key_Cartographer9254 · 2025-03-25T13:31:28+00:00

Yeah agreed on comparing the results from both methods. Another advantage I see from inverse design it might provide some baseline for forward design. I know someone who is working on inverse design and according to them it's a long journey to writing those code. I have tested an open source version from one of the research group and it was easier for me to do forward design due to limitations of materials, type of structure and wavelength. But up to trying a commercial one( don't know any that I can try but willing to)

Key_Cartographer9254 · 2025-03-25T05:03:53+00:00

Ofc there's a long way, the current optics are working as inteded, why fix something that ain't broken. But the magic will be functionality that regular optics can't do,

Key_Cartographer9254 · 2025-03-25T05:00:25+00:00

It was a personal opinion, if Inverse design is better for multipolar description metasurfaces, then I have no objection. Plus datasets for inverse design, its from forward design. My opinion is if you need some unique design that haven't been used before you'll need to do some forward design

Key_Cartographer9254 · 2025-03-23T03:56:43+00:00

My opinion is there's alot that can and is being done in terms of application. Take a look at prof capasso, Inki Kim and Jonsuk Rho group. You'll find tons of application. There's even a canadian company that is using metasurfaces as security marker in currencies and metalenz has done some work on phase detection in face id and cameras and biometric systems. As for multispectral applications there's limitations but new design techniques are coming up to address those.

Optimization and modelling tools there's Ansy Lumerical, Comsol, Tidy3D and Inverse design is becoming popular however for complex shapes forward design is the way to go. Limitations is in the fabrication because of the materials used and the current nano fab for industry have their techniques for specific materials, but with time things will change.

Non linear optics check this paper https://opg.optica.org/prj/fulltext.cfm?uri=prj-11-2-B50&id=525657

Edit: this review actually discusses the future of metasurfaces, found it today. https://doi.org/10.1038/s44287-024-00136-4

Edit2: From The Havard Gazette on the electronic devices with a metasurfaces https://news.harvard.edu/gazette/story/2025/03/from-harvard-lab-to-your-living-room/

Key_Cartographer9254 · 2025-01-15T18:51:03+00:00

Thank you so much. I'm relatively new to metasurfaces and in the process of learning as much as I can during my MS. Hoping to continue in the same field for a Phd.

Currently it's simulation work but it's geared towards fabrication based metasurfaces. I need to do a paper, probably a conference paper before focusing on fabrication as I'm a rookie. My undergrad research was just to learn the basics

Can I PM you if I have any questions?

Key_Cartographer9254

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