Fourier Optics used for Optical Pattern Recognition @HuygensOptics

Huygens Optics | Fourier Optics used for Optical Pattern Recognition @HuygensOptics | Uploaded July 2020 | Updated October 2024, 1 hour ago.
Optical Fourier transformations were performed using small lithographic patterns of different characters. A DLP projector can be used as a Fourier filter to do simple pattern recognition.

Video contents:

0:00 General introduction
1:44 Fourier explained (simple)
3:45 Digging a bit deeper (sorry, could not resist)
5:55 Fourier on images
9:27 Fourier transforms using optics
12:05 Setup and results
14:15 Fourier filtering

The 2D Fourier transformation images were calculated using freeware developed by Kobe University. You dan download this tool from:
cas.eedept.kobe-u.ac.jp/WelcomeES1/OpenSoft/FFT2D/index_en.html

Conversions of 2D images to 3D were done using Gwyddion. This very advanced piece of software is can be downloaded for free from:
gwyddion.net/download.php

To illustrate 2D Fourier transform on an actual image, a small part of an M.C. Escher drawing was used.

While editing the material for this video I found out that the Applied Science channel made a somewhat similar video on "Optical Fourier" already in 2012: youtube.com/watch?v=wcRB3TWIAXE . Luckily the angle is somewhat different.

This video gives a different (and deeper) perspective on the math behind Fourier transformations;
youtube.com/watch?v=7mkn47hqqkc

If you want to go all the way, read the wiki page on Fourier. If you dare.
en.wikipedia.org/wiki/Fourier_transform

Optical Lens Centering using a LOH LZ-80.

Curve Generation using a Milling Machine (Short Impression)

$Maskless Wafer Stepper Part1: Optics Ive been planning to make a maskless wafer stepper for a long time. In the last few months, I finally found the time! This video is the first of 3 videos on the design- and build process. It discusses the optical aspects of the machine. 0:00 General intro 0:38 About Wafer steppers in general 1:12 Meta surfaces and flat optics 2:00 Principle and advantages of a maskless wafer stepper 4:36 Projection optics 6:47 Global layout of the machine 8:50 System overview I hope to make micro optics with this machine in the near future. By the way, not the standard meta surfaces, because the resolution will be too limited for that, but meta surfaces that combine both refractive and diffractive functionality. Currently Im still in the building process of the machine and the software. I have taken the liberty of using a few short clips in my video. Please give the makers credit by visiting the original videos or websites if you are want to know more: ASML video on EUV-wafer steppers: https://www.youtube.com/watch?v=jH6Urfqt_d4 Great video by science magazine with entry level info on meta surfaces https://www.youtube.com/watch?v=ETx_fjM5pms If you want to go a little deeper: https://www.youtube.com/watch?v=RBGwJE0ww7s https://www.youtube.com/watch?v=3qeE5A8HIWY https://www.youtube.com/watch?v=AM4yO0mjR4g By the way, the Nikon objective was bought at https://www.ebay.nl/usr/avr-sales. They gave me a very good price and exceptional service, so make sure to check them out for used tech stuff.$

CNC Radius Milling in Optics: the LOH Spheromatic Curve Generator.

$Making a Monolithic Telescope Part 1: Optical Design and Aspherics. Video Contents: 00:00 General Intro 00:56 Spherical is easy 01:32 Aspherical is hard 01:59 Ideal lens vs. spherical surface lens 03:17 The concept of the light ray 04:47 A little optics quizz 06:21 Optimum spot size using iterative numercal analysis 07:56 Use of optical design software (Zemax) 09:45 Theory of aspherics 10:54 Conical aspherics 12:02 Polynomial aspherics and even aspheres 14:24 Numerical optimization in aspherics 15:30 Effect of introducing an aspherical surface 16:55 Optical design of monolithinc telescopes 18:23 Material choice and CTE 20:52 Classical Cassegrain configuration 22:10 Schmidt Cassegrain configuration If you want to support the production of these videos, you can now become a Patron of the channel. You can find more information on : https://www.patreon.com/huygens_optics Reference to my original video on tiny monolithic telescopes: https://www.youtube.com/watch?v=HxwhCmO90UQ LInk to my video on conics: https://www.youtube.com/watch?v=WIl6FlUCHQg For the record, I do not have any commercial ties to any of the companies or individuals that are linked below. Zemax page for requesting a trial license of Optic Studio: https://www.zemax.com/pages/try-opticstudio-for-free If you want to know more about the workflow in Zemax, the great tutorial videos by Scott Sparrold of OpticsRealm are a good start: https://www.youtube.com/user/opticsrealm/videos Youtube video discussing the optical design of the James Webb telescope: https://www.youtube.com/watch?v=OE3ZowuvAJY The Thorlabs page with aspheric lenses and the formula: https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=3835 I used a few short clips from the following Youtube videos, assuming this use is covered under the fair use policy by placing references to the channels and links to the corresponding videos in the description. Clip from Yuri Petrunins polishing 210mm lens: https://www.youtube.com/watch?v=ipwnK45_Kf4 Clip from Edmund Optics How an Aspheric Lens is Made: https://www.youtube.com/watch?v=CVDT3u1La6w Clip from Learn n hv fun Refraction of Light Through a Glass Slab[...]: https://www.youtube.com/watch?v=el8AUeZaljw Did I forget to mention you here? Let me know and I will set things straight.$

Building a Small Cleanroom for Photolithography.

Optical Lapmaster Machine for Polishing Flats of Glass pt.2 (short impression)

Light & Coherence part 1: Temporal Coherence

How to make Very Flat Optical Surfaces on Glass

Maskless Wafer Stepper Part 3: Electronics and Software.

Photomasks Explained (Contact and Projection): how to etch Thin Chromium Layers