Micro Lenses made with Photolithography.
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- เผยแพร่เมื่อ 16 มิ.ย. 2024
- I'm quite excited to show you the focal properties of my microscopically small lenses that I made using photolithography. These lenses are actually Fresnel zone plates which use diffraction as the method for focussing the light. They were made using the DIY maskless wafer stepper.
The lenses have more than one focal plane, and you can easily observe the 1st, 2nd and 3rd order focal planes when they are used in combination with monochromatic light sources.
I used a static image from a video on meta surfaces. Please check out this video if you want to know more about this subject: • Shrinking microscope l...
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Really cool. Your videos are so interesting! One thing you might try: put liquid crystal onto the diffractive element. By adjusting the electric field, some lc materials will shift refractive index, matching the pattern, or not matching it. Basically, an electrically tunable optic.
Thanks Ben, I think it's a great idea to look at the possibilities to change/modulate properties of micro optics by using electric fields. By the way, the shift in refractive index in the configuration you suggest would not change the focal distance of the lens, since this is only dependent on the spacing in the grating. But in fact you could make it switch between a clear state and a "focal" state.
P.S: love the Applied Science channel. It's one of the reasons why I started making these videos!
If you want more efficiency from your two-focus lens, instead of simply adding the two patterns together, use an XOR function. In other words, in a given location if both patterns would be black, make it invert and turn white. The patten will be restored to 50% 1 and 50% 0 and you'll have higher efficiency with no downside.
You are completely right. For this particular example I just added two diffractive patterns together in photoshop, which is a very crude method. For example, you also see ghost-focal points pop up right in the center between the two focal points. So I will try you suggestion in future mask design. However I still have to write software for that. Thanks for your valuable suggestion.
@@HuygensOptics Photoshop has this option. Make 1 black/white layer for each zoneplate. Then apply the "difference" feature in the layer pulldown menu. It's on the of the options for showing how layers are combined. Like normal, dissolve, darken, multiply, etc. That will do it in one step!
"How cool is this?" I will tell you. Super cool.
Now that’s crisp optics
glad youtube algorithm introduced me to your channel.
Great work, thanks for sharing. I would have loved a system like this for faster prototyping of microoptics...
Thanks for share such beautiful information!
Hm, I think the color aberration could serve to target specific light frequencies, by laying a grill of lenses matching the pixels of an unfiltered black-and-white camera; and by adding a control-knob or some sort of automated adjustment, you might even be able to get per-pixel spectral data by sweeping over the different frequencies' focal planes over several frames.
excellent work👍
You. are. just. awesome.. I work in research institute and looking on your publishing dates, I can say - you are damn fast with realisations of your ideas.
Wow, nice Job!
"How cool is that?" Very cool! :) Have you considered making hybrid optics? E.g. pattern a diffractive lens on top of a singlet lens to make a "hybrid achromat"? Or I guess on top of an achromat to make an apo? I suppose that could be fairly challenging, since you'd have to model the curvature into the projected mask, and deal with out varying focal plane of the lens. But maybe possible if the ROC is very shallow? Dunno, this is super cool stuff, congrats on getting it working!
Thanks for the suggestion. I guess it should be possible especially with for example plano convex lenses. In theory you can make really special optics. by the way: It's already available in commercial systems: cpn.canon-europe.com/content/education/infobank/lenses/multi_layer_diffractive_optical_element.do But in order for me to do this this kind of stuff, I first need to get the pattern "stitching" perfect (currently working on this). Otherwise I can just modify the surface of lenses with a diameter of 0.4mm which is not very useful in the practical sense.
@@HuygensOptics Ahh that's a good point, I wasn't thinking about it require stitching to be useful/practical. Guess that's just one more piece of motivation for stitching :) Keep up the great work, really enjoying all your videos so far
Fascinating. two applications (I'm sure this is nothing novel) regarding the overlapping lenses. The most obvious would be stereoscopics or range finding. The second could use them as color detection based on the color dispersion principle you animated.
Great results! If you put an array of these on an image sensor, you could make a Shack-Hartman tester. You could also try making some CGH patterns that project images when illuminated with a laser pointer. There is a negative photoresist called SU-8 that slumps when heated and is often used to make refractive microlenses. If you could use this technique to convert your rectangular line profile to a more sinusoidal one, it might reduce the higher orders (but not the -1 order).
Thanks Adam, great suggestions! The Shack Hartman wavefront tester was actually already on my mind. It would just involve sticking one of these arrays to a CCD sensor at the focal distance. With a laser you can get 1st order spots which are diffraction limited. I think my current patterns are already a bit wavy, especially in the outer perimeter where the resist is only partly developed. Anyway: to be continued...
Optics is very interesting science thank you for your explanation, I like it.
Amazing.
If you can make tiny prisms and match them to the grid of a image sensor, you could have a refractive colour filter.
That should have advantages, especially in low light, compared to classic absorbing filters.
Until I saw this video, I had no inspiration how to realistically make one.
This is one of the coolest project on YB, well done.
love the channel. I would love to make metal dielectric slab lens if I had vacuumed metal deposition chamber and micro lithography workshop !
one thing you can do to get started with a lower resolution at first is to design elements for CO2 laser light - though I understand observing the result will be made more difficult...
Good video
Cool, like little star photos from Hubble telescope. Can we extract or refocus the original layers from star photos by simply back stepping diffractions and chromatic dispersion with special algorithms ?
I have a somewhat unconventional idea for maskless lithography that I've been researching recently - microfocus x-ray tube transmissive anode targets, where the main "focusing" is done by using a conductive, very low x-ray generation substrate(beryllium or diamond foil) with a single, tiny(100-5000nm diameter, 1-50um thick) metal(Mo or W) target dot deposited on it, rather than having to focus the electron beam to the same micron scale, which is very complicated.
Once I get around to prototyping this x-ray tube, I will be following your DLP stepper's footsteps, though a bit simplified :)
You definitely have a new subscriber.
Sounds like a pretty advanced project! If you ever publish about it or make a video, please let me know.
@@HuygensOptics I will be making videos about this project when I get to it. Working on the high vacuum system at the moment, and then lots of other steps before x-rays.
Dislike ratio in this video is the wildest on TH-cam... You need a reward!!
Thanks for share such beautiful information!!!! Focus an laser at lens put water with microbians to see in the wall?
Could you make a micro patterned macro lens with this method? Would be cool to play with that.
This could have interesting applications for fibre communications such as ROADM DWDM implementations...
Great project! Have you heard about "photon sieve" concept? Maybe it is worth trying?
Now, that is a really cool suggestion. You just filled up my Easter weekend with new experiments.
Something like a double focal point lens looks like it could be used to see stereograms with having to go through the process of seeing them.
Hi.
I started with Sam`s maskless projector and youtube recommendations showed me your channel. Now I'm making my own maskless system (not stepper at the moment) I have hacked and DLP projector to emulate the ballast of the lamp and now I can operate the optics with leds and othen iluminations. Hg lamp is dangeorus an too much powerful. I also have a trinocular microscope, but maybe I'll follow you and take your idea of the maskless machine. My goal is to make microcircuits, maybe microlenses just for fun and maybe semiconductors. But the real goal is to finish the machine. Thank for sharing your experiences and I hope I can share my own experiments soon. Best regards from Spain
Looking forward to that, let me know if you do. Good luck!
Sure!! I have no idea about submicron devices, and I see that you recommended some people to concentrate his efforts in the precision of the stages. I'm a little bit afraid now about the magnitude of the project, including the sofware and the squareness calibration (I don´thave a calibration mask rigth now). Now I'm waiting for a beam splitter, cameras and other stuff, and I'll continue the work slowly. Best regards from Spain
Can you use this setup to make better lenses for the stepper? Would that even be possible?
that is the coolest shit!!
Could these be (or are these already) used in a Shack-Hartman wavefront sensor?
by releasing your research in a public forum and having new stuff you are working on it helps keep you from being blackmailed or worse. photonics is that sort of field. for small scale IC manufacture i have thought lab-on-chip, a little clean room with all the needed out/inlets and with leads out the bottom might be a good approach. with a window at top for the photolithography to work. also, why dont people's furnaces generate electricity for their homes if they are to make BTU anyway? awesome channel
Could the Double focal point lens lead to 3D optics for holograms?
Augustin-Jean Fresnel was a genius.
7:32 looks kinda beautiful tho
Hello, I was wondering: What program did you use to make the lens with two focal points?
If they work to make smaller images; can you also use them to magnify tiny things by placing the tiny things at the focal points?
Yes they are basically small microscope lenses (of course with a high chromatic aberration)
Any time I am reminded of Fresnel zone plates, I wonder why we don't use them as vision correcting lenses. Are they too expensive or too impractical (or both) with our current tech? Is the chromatic dispersion too great?
I'm not as well-versed in optical engineering as I'd like to be, so I'm probably missing the answer that would be more obvious to a professional.
Did you ever think of making Hopkins Relays with these lenses? I think this would be very pleasant to play with these making ultra miniature endoscope tubes.
In general, the chromatic aberrations are quite large, so unless you discard color information and use monochromatic light, the image quality will not be sufficient for an endoscope.
@@HuygensOptics Hmm... I'm fantasising now...
What if you deposit a triple layer of three different kinds of diffraction patterns with each layer blocking just one wavelength band. Spectral notch filters are not uncommon in optics today. In this case the focal plane of each colour band could be positioned at the same distance to the "lens".
I know its crazy but maybe somehow feasible?
@@ghlscitel6714you mean like this? th-cam.com/video/TshYfYIxR9E/w-d-xo.html at around 2:47 minutes
@@HuygensOptics I am impressed. What you have made is even a few steps further. Yes, your experimental results inspire to think further into this direction.
3:05 i've seen too much AvE videos, and every time when i see something like that, i can hear voice in my head saying "focus, you f%ck!". Anyway, thank you for sharing youre science experience. Very interesting, need more details, i love things like that.
could you make a cheap compact autocollimator
I guess that is also possible, when you use it directly in combination with a CCD-camera. Thanks for the suggestion.
One thing ive wondered: why don't smartphones and other small image sensors with fixed lenses use a microlense array?
Are you planning a SH-Sensor?
Yes actually I've already made one and I will discuss it in the next video. It's been very busy lately with work but I hope I can get the new video out in a few weeks time.
The first thing I think of is obviously a laser but I don't know if it would work.
Another thing I'm thinking of is to use this kind of lens to project patterns for lithography. Maybe it could work?
Hi
Ooohh , stereoscopy.