Optical Engineer Rik ter Horst shows us how he makes very small telescopes (at home) which are intended for use in micro-satellites. Contents: 0:00 Intro 1:06 About telescopes and focal length 3:35 The Cassegrain telescope 4:38 The Schmidt-Cassegrain telescope 5:18 The monolithic telescope concept 6:30 Rik ter Horst Interview 10:25 Riks' polishing setup 13:51 About manufacturing aspherics 16:50 Advantages of solid telescopes 17:49 Dreaming about a VLTT
ORESAT PROJECT CORRECTION. I was notified that the name of the university behind the OreSat project is erroneous: It is the "Portland State University" (https://www.pdx.edu/), not University of Portland. Sorry about that! Direct link to the Oresat project: oresat.org
Optical Engineer Rik ter Horst shows us how he makes very small telescopes (at home) which are intended for use in micro-satellites. Contents: 0:00 Intro 1:06 About telescopes and focal length 3:35 The Cassegrain telescope 4:38 The Schmidt-Cassegrain telescope 5:18 The monolithic telescope concept 6:30 Rik ter Horst Interview 10:25 Riks' polishing setup 13:51 About manufacturing aspherics 16:50 Advantages of solid telescopes 17:49 Dreaming about a VLTT
ORESAT PROJECT CORRECTION. I was notified that the name of the university behind the OreSat project is erroneous: It is the "Portland State University" (https://www.pdx.edu/), not University of Portland. Sorry about that! Direct link to the Oresat project: oresat.org
Do you like what I do and want to support it? I'v recently started a patreon page: patreon.com/huygens_optics
Did I forget a reference? Objections? Please let me know and I will set it straight and add a link.Using a Photomultiplier to Detect Single PhotonsHuygens Optics2024-09-11 | Photomultiplier (PMT) principle, operation and measurements explained.
00:00 Intro and overview 00:30 The photoelectric effect 02:11 Detecting single photons 03:33 How a PMT detects a photon 10:35 How to operate a PMT 17:00 Measurements with a photomultiplier 24:59 Conclusions
The video contains 2 short clips taken from other Youtube channels: @reps and @ElectroBOOMKnowing the one-way speed of lightHuygens Optics2024-06-29 | So you think you have a brilliant idea about how to measure the one-way speed of light, only to discover that it contains a very trivial oversight. Luckily this initial failure was the start of a few new insights on the relationship between one-and two-way speed of light. Well, at least new to me...
What do you think: is there a way that the one-way speed of light is not identical to the two-way speed of light?
Content: 0:00 Introduction 0:30 Origin of the two-way speed of light definition 1:40 The Fizeau speed of light experiment 3:27 Trying to measure the one way speed of light (and fail) 12:07 Speed of light from the wave perspective 18:24 Problems related to opposing anisotropy in vacuum 21:23 Violation conservation laws (abstract) 22:23 But... when spatial anisotropy changes with time...
The video contains 2 short clips of the following videos: @Veritasium: youtube.com/watch?v=pTn6Ewhb27k&t=626s @AlphaPhoenix: youtube.com/watch?v=YMO9uUsjXaI Thumbnail in light of Yoda's Light Sabre from Star Wars For the simulations, I used a Python script supplied by @DiffractionLimited
End music: Floating - Earlybirds Special thanks to Physbuzz for interesting views and discussions. If you enjoy coding waves, check out this page: mathandcode.com/2024/04/21/waveequationint.htmlMeta lenses explainedHuygens Optics2024-05-13 | How a meta lens refracts light. Wave simulations done with the Python script supplied by @DiffractionLimited
Erratum: 1) The gravitational constant has a missing minus sign in the exponent. The value should be 6.7x10^-11 N.M^2.kg^-2.
The idea of a Gravitational Index of Refraction is not new. Here is a reference to a recent article by D.H.W Reffer (date unknown but after 2018): vixra.org/pdf/1903.0407v2.pdf
Wave simulations were made using the python scrip provided by @DiffractionLimited YouTube channel. Link to the code download: github.com/0x23/WaveSimulator2D
Animation of the dancing quarks at the end of the video by "Arts at MIT".
Royalty free music used: Cat Circus - Doug Maxwell Always Remember to Never Forget - The Whole Other Yoga style - Chris Haugen Thanks very much for making this! End tune: Floating - Early Birds
In the video, the simulations were sometimes paused to relieve the YouTube compression algorithm and the viewers' eyes a bit.
Did I forget anything? Let me know and I'll set it straight.Gradient Index Lens ExplainedHuygens Optics2024-03-12 | This is short is about how a Gradient Index Lens (or GRIN lens) works compared to how a normal confocal lens with curved glass interfaces operates.
The diffraction inside the lens is probably due to the fact that the refractive index gradient is not exactly correct. The total gradient is approximated from 5 linear gradients instead of 1 smooth circular gradient. This is probably the reason for the observed interference pattern observed.
The simulations were made using the code supplied by @DiffractionLimited
Music: Nebular Focus by Dan Henig
#optics #light #physicsExploring White Light Interferometry! (WLI / CSI)Huygens Optics2024-03-03 | Creating 3D-maps of reflective surfaces using White Light Interferometry (WLI, also known as Coherence Scanning interferometry).
Content: 0:00 Intro 1:43 Building a White Light Interferometer 4:39 About spatial coherence 7:11 Observing interference in white light 10:37 Broad-band radiation interference explained in detail 21:11 WLI Microscope Zygo Newview 100 explored 23:16 Measurement examples 25:44 Michelson and Mireau objectives 26:56 Concave spherical mirror surface (measurement) 27:44 Granite surface structure (measurement) 28:47 Etched glass surface (measurement) 29:32 Turned stainless vacuum part surface roughness (measurement)
The simulations starting from 5:12 have been made using the python script produced by @DiffractionLimited. This code can be downloaded from github.com/0x23/WaveSimulator2DWave frequencies passing a gratingHuygens Optics2024-01-31 | This video shows a simulation of a transmissive grating on a glass plate that sends different wave frequencies in different angular directions. In the second part it show how it also does this if the incoming wave is a linear sum of 3 different frequencies. Thereby it performs a Fourier transform on the incoming wave signal (time domain) to intensity in an angular direction (a spectrum in the frequency domain) It was reuploaded because the original version contained an annoying error in the frequency indices.
The Python code used for the wave simulation can be found on the @DiffractionLimited channelAbout Laser SpeckleHuygens Optics2024-01-27 | The video shows a simulation of a phenomenon called "speckle". It's best known as the granular interference pattern observed if we shine a coherent light of a laser at a diffuser. You can also observe it from a medium that contains small scattering particles. The simulation shows that it is caused by small phase differences that are introduced in the light by non-uniformity of a medium
The green laser speckle image is taken from Wikipedia (copyrights Steve Jurvetson) and shown here under the Creative Commons license 2.0 (creativecommons.org/licenses/by/2.0)
Simulations made using the Python code suplied by @DiffractionLimited
#physics #lightCoherence in star lightHuygens Optics2024-01-18 | This short discusses (very briefly) the difference between temporal and spatial incoherence. It also contains a wave animation of a telescope mirror that concentrates a field on a sensor. Of those of you who want to know more about coherence I made these videos: Temporal coherence: youtube.com/watch?v=dtcq5b0R65w Spatial coherence: youtube.com/watch?v=nba4ztLBEh0
Presented here are 2D-animations of a field, which means that the intensity of the focused light at the sensor increases with the diameter of the mirror. In a 3D scenario however, the intensity increases with the square of the diameter of the mirror, leading to a much larger difference between the incoming and focused radiation intensity.
#short #light #physics #opticsInterferometer InterferenceHuygens Optics2024-01-16 | This short video shows how the intensity distribution changes in a wave interferometer, when one of the mirrors is moved by 1/4 of a wavelength. A shift by 1/4 wavelength in the mirror position introduces a phase shift of 1/2 lambda (180 degrees phase shift) and introduces "destructive interference" in one of the wave return paths). You can see that destructive interference is actually about rerouting the intensity to somewhere else: in this case, the waves return in the direction of the wave source itself (located above the beam splitter), create a standing wave pattern between the incoming and outgoing waves. This wave simulation was made using the code supplied by @DiffractionLimited The image file for the simulation can be downloaded here: huygensoptics.com/2D_wave_sims/interferometer.png
#short #light #physics #opticsIncoherent Wave EmitterHuygens Optics2024-01-10 | This simulation shows a spatially- and temporally incoherent wave emitter that consists of around 100 individual wave sources. The sources are continuous but all have a slightly different emission wavelength. This results is the emission field and intensity distributions shown in the video.
#physics #light #shortDirectional coherent wave sourceHuygens Optics2024-01-09 | This short shows a directional wave source that is made by spacing omnidirectional wave emitters in a very specific configuration. The animations were created using the wave simulation code made by @DiffractionLimited
As for the question at the end of the video about being able to spot how destructive interference comes about: this is basically impossible to see in the animation. So the answer to the question is NO. However, there are few ways that you can look at how the phenomenon comes about: 1) When moving away in the horizontal direction of a row of emitters, for every point there is an equal amount of emitters that has a particular phase, compared to the emitters that have a phase 180 degrees shifted. So, when adding up these 2 contributions for all the emitters together in a row, this results in a wave amplitude that is almost zero in this direction. 2) An alternative way to look at this is the following: because of the spatial separation of exactly 1 lambda in the vertical direction, a standing wave arises in the array that has almost equal field strength in the horizontal direction within the array. And because the sources are moving in phase with the standing wave, they cannot transfer energy into the surrounding field in the horizontal direction. This also explains why a low intensity in the horizontal direction exists.
Both views are in my opinion valid, but I think the second one is a bit more intuitive.
#light #physics #optics #shortImaging at ASMLHuygens Optics2023-12-21 | A visit to ASML with a deep dive into diffraction and imaging: 0:00 Intro 3:14 How big big are chip patterns nowadays? 5:00 Arriving at ASML Veldhoven 5:50 Interview Sander Blok part 1 7:40 About diffraction and image formation 9:36 Fraunhofer (far field) interference / diffraction explained 11:15 Diffraction on photolithography masks 15:11 About critical dimension 17:27 Example of computational photolithography 19:23 Interview Sander Blok part 2 21:46 EUV is difficult...
by the way, the frequency of the tin droplets apparently is 50.000 not 15.000 per second.
Did I forget anyone? Please let me know and we will work it out.Ray/Wave Racing Championships 2023 #light #physicsHuygens Optics2023-12-04 | This wave / lens simulation was made using the Python wave simulation script provided by @DiffractionLimited.
The link to the source code on github can be found in the description of this particular video: youtube.com/watch?v=N5a06o3ghzUHow a Lens creates an Image.Huygens Optics2023-11-24 | Contents: 0:00 Introducing "rays" 2:14 Light is a wave 4:00 Nils reached one thousand! 4:43 Effect of Numerical Aperture 6:46 About "Critical Dimension" 7:40 Effect of NA illustrated using a microscope 10:44 Diffraction in the Double Slit Experiment 12:30 Diffraction in the Circular Slits (Fresnel Zone Plates) 14:40 Effect of central obstruction on focus 15:05 Using diffraction to create an Image 18:59 Comparison to the Fourier Series Approximation 19:44 Image Creation and JPEG compression 20:59 Effect of wavelength on definition 21:35 Extroduction
Some images were taken from JW Middelink Systematische Natuurkunde Deel B. This book series is absolutely awesome. They made me enjoy my high school physics classes and that is why I held on to them for 40 years.
The video contains a short audio clip that is inspired on "another one bites the dust" by Queen. I did not use the original drums and bass but, Freddy himself did contribute in his own special way. I consider this fair use but if you are the copyright owner, please contact me in case you consider this a copyright breach. Today on the date of video publication it is 32 years ago exactly that Freddy Mercury died of Aids.
Apparently, the lady in the compression images is named Lena. If I had known the history behind the image and why it became so famous, I would probably not have used it: https://pursuit.unimelb.edu.au/articles/it-s-time-to-retire-lena-from-computer-science
A correction about the name of ASML: currently, this is the actual name of the company, so without any reference to the origin of the abbreviation. Advanced Semiconductor Materials Lithography was the name of the joint venture of ASM (founded by Arthur del Prado) and Philips Electronics, intended for the development of photolithography machines.
Did I forget to mention you? Please contact me and I will sort it out.Optical Interferometry Part 2: Measuring Optics with a Zygo GPI LCHuygens Optics2023-10-02 | This is the second video on optical interferometry, which is dedicated to measuring the wavefront shapes of a mirror, 2 lens assemblies and 3 microscope objectives.
Contents: 00:00 Intro 02:04 Video camera upgrade 04:23 DFT-fringe software 06:57 Transmission Sphere reference calibration 12:29 Shape of a Zerodur Perkin Elmer wafer stepper mirror 14:55 Wavefront deformation of a Canon FD f/1.2 camera lens (1980) 18:10 Wavefront test of a modern Canon EF 24-105mm f/4 zoom lens 19:19 Microscope objective testing 22:44 Nikon Plan Fluor 10x / 0.30 23:17 Leica Fluotar 20x / 0.50 25:23 Nikon Plan APO 20x / 0.75
Do you need to be referenced but I forgot to do that? Let me know and I will set it straight.The double beam experimentHuygens Optics2023-08-13 | A bit of optics fun and a little riddle: two coherent light beams of equal intensity and opposite phase meet up. They interfere destructively in the center, thereby creating a continuous plane of zero EM field (and so of zero intensity). The question is: how can the energy in either beam cross and area of zero intensity? Leave a comment if you want to show off your intellect ;-).
The experiment in the last 20 seconds of the video shows the cross section of 2 laser beams that meet up and part again. For the experiment I used a single coherent source (HeNe-laser), because that is the only way this experiment could work. It requires a fairly high degree of coherence. Basically it's just a 50% beam splitter and an adjustable mirror under 45 degrees, that create 2 beams of equal intensity, initially spaced 4mm apart, 1mm in diameter and are under an angle of 0.1 degrees with respect to each other. I moved the camera sensor over a distance of 6 meters and recorded 40 images around the area where the beams were crossing paths.
BTW: officially, I think there is no such thing as the "double beam experiment", I just made that name up...Optical Interferometry Part 1: Introduction & ZYGO GPI layoutHuygens Optics2023-08-04 | The video discusses the principles of optical interferometry using glass interfaces and a ZYGO GPI LC interferometer from the 1990s.
0:00 intro 2:13 What can you do with interferometry? 3:06 Optical wave fronts explained 12:41 Inside the ZYGO GPI LC interferometer 20:45 Example of visual fringe evaluation
The clip featuring a wave at 3:12 min was taken from this FailArmy video: youtube.com/watch?v=r-V_r0UTs0g For much more fails, visit their channel: youtube.com/@failarmyCoherence part 3: This is not a wave.Huygens Optics2023-05-26 | Trying to find analogies between the wave energy confined in a string and matter interacting with light.
0:00 Intro 6:38 Experiments with waves in a string 15:40 Analogies with electron behaving as waves 22:50 Changing the standing wave mode in a string using phase manipulation 26:49 A hypothetical model for demonstrating quantized wave behavior in a string 32:26 Elastic-Inertial Poetry
For this video I used a a few short clips from the following videos and websites:
Did I forget anybody? let me know an I will set it straight.Light & Coherence part 2: Spatial Coherence (and the Double Slit Experiment)Huygens Optics2023-02-27 | Second video about Light and Coherence. Contents: 0:00 Intro 0:38 Real life demo of spatial coherence (Lorentz pond) 2:14 Numerical wave simulations (Nils Berglund) 5:05 Area of Coherence explained 8:07 Calculating the Area of Coherence of the Sun 9:10 Spatial coherence and the double slit experiment 10:41 About the use of metaphors in science 12:45 Double slit demo without & with spatial coherence 15:43 Spatial coherence of light from far away stars 18:13 Quantization and semantics 20:39 Credits
The video contains simulations made by Nils Berglund: here is the link to the original full video showing you both the wave patterns as well as the energy distribution on an eLog scale: youtube.com/watch?v=8TBi9eafNII Link to Nils' channel: youtube.com/@NilsBerglund/videos
Contents: 0:00 Intro 1:04 Historical perspective 2:58 Quantization and the photoelectric effect 6:42 Light is just waves 7:24 Coherence explained 12:54 Temporal coherence as a sum of EM-fields 16:47 Coherence length vs. spectral band width 20:25 experiments on the coherence length of light
A sharp viewer noted that there is an error in the formula on the sheet at 27:25 : The product of delta time and delta energy in the Heisenberg uncertainty principle is not equal to (h*4*pi) but h/(4*pi), so a much smaller value. This also makes the value of delta frequency times delta time 1/(4*pi) not 4*pi Unfortunately I did not double check the values. Thanks for pointing this out Steve.
In this video short clips of other YouTube channels were used for illustration. Because of their short length and purpose, they are to be considered to be "fair use". @TheActionLab @TechIngredients @ArvinAsh @pbsspacetime youtube.com/c/veritasium @upandatom @ProfessorDaveExplains youtube.com/user/lookingglassuniverse Did I forget anyone? Please let me know and I'll set things straight.
Contents: 00:00 Intro 01:23 The inside of a Soligor mirror lens 02:51 Using second surface reflectors 06:06 problem located 08:25 Measuring sharpness quantitatively 09:30 Introducing MTF-mapper 10:08 MTF explained 12:30 MTF-mapper software explained 15:25 Comparing lens resolutions 18:38 How to make optics sexy (NOT)
Link to part 1: youtu.be/x2BiM7BGQMU Download URL for MTF-mapper: sourceforge.net/projects/mtfmapper Many thanks to Frans van den Bergh for building this great software tool. Thanks also to Sergey Kotikov (Сергей Котиков), for pointing out the software to me.
The music video was produced by Dr. Liam Fullersheit, who performed the rap, did the arrangements, mixing, and most of the choreography. Whether our CCO actually succeeded in making optics "sexy" and attractive is still the subject of fierce debate within the Huygens Optics organization. The video clip was made as a tribute to 70s and 80s funk and heavily inspired by the music of Rufus and CK. If you are into this kind of music, please check out their Topic Page: youtube.com/channel/UCV-ePMa7s-AqUtVYysArFug. In case you need to be mention here as a copyright owner, then please contact me.
Because of multiple requests, I posted the Lyrics of the song below. There were a few concerns about the ambiguity of some of the frases. Dr. Liam reassured me that there was no reason to worry, since it is basically just a song of praise about his favorite camera lens.
"It's 2022 and it's high time to shine some lights on optics My name is Liam, I'm funk optician I scan the room with my laser vision You don't need a high power lens to see I'll have my MTF on MTV
We'll grind all through the night my dear, until every surface is a perfect sphere I can feel your fringes when we interfere So let's transfer modulation right here
The spread function pointing your direction Is on an optical axis made for satisfaction No spectacles needed for you see, we're a perfect match, chromatically
And dilation is what will occur, when I focus on your aperture So if you image me, the way I image you there are infinite conjugate things to do
Shine your lights on me I can make you see..anything I can make you see..anything you want baby Oh baby, you're so sharp"Camera Mirror Lenses Part 1: Visual and Interferometric TestingHuygens Optics2022-10-27 | In this video I will discuss the visual and interferometric tests of camera mirror telephoto lenses. Contents:
0:00 intro 1:16 Vivitar f=800mm F:8 mirror lens 4:58 Sigma f=600mm F:8 mirror telephoto 7:34 Soligor f=500mm F:8 mirror lens 8:26 Explaining interferometry in auto-collimation 12:09 Actual interferometry measurement setup 14:58 About Strehl Ratio 17:15 Strehl ratio and aberrations of Vivitar 800mm mirror lens 18:18 Comparison with results of Sigma 600mm mirror lens 20:17 Extro
Tommy Cooper photo: https://panorama.nl/artikel/174764/komiek-tommy-cooper-stierf-35-jaar-geleden-in-het-harnas
End music: "Floating" performed by the Early Birds (recorded in Eindhoven in 2000).
Did I forget to mention you above and are you a copyright owner? let me know and I will set it straight by linking to your original content in these credits.Not a photon in sight! [#shorts]Huygens Optics2022-10-11 | #shorts, my first one (and maybe my last!) The video video illustrates how the Electromagnetic field inside a laser beam can locally be made virtually zero creating destructive interference. This is achieved by just placing a pinhole of the right size inside the beam. The size of the pinhole for this experiment is around 25 microns.Bathroom Quantum Fields and Vacuum EnergyHuygens Optics2022-09-21 | Building a bathroom got me all philosophical. Video contents: 0:00 Intro on Bathroom energy 1:51 About energy conservation 3:38 Wave character of particles/matter 5:06 Concept and value of vacuum energy 11:08 When theory takes a silly turn 12:25 About probability in QM 16:09 What is a measurement? 19:27 How to get away from vacuum energy 20:13 Wave behavior in classical systems 21:23 Conclusion
This video does not contain serious science experiments and is purely based on hearsay and guesswork.
In the final part of the video, I used some video material previously featured in a video about oil droplets with quantum-like behavior on the Veritasium channel. The video in question: youtube.com/watch?v=WIyTZDHuarQ I guess the video content was copied from this video 2012 of MITMathLabs: youtube.com/watch?v=nmC0ygr08tE I think they might very well be the original content owner. The main website of this research can be found here: http://dualwalkers.com The original footage filmed by Raquel Nuno
Some of the best videos on theoretical physics can be found on the channel "Physics Explained". These videos give more info on the background of how particles and vacuum energy arise from quantum fields in a mathematical context: youtube.com/watch?v=8loIYt4QKqQ youtube.com/watch?v=QPAxzr6ihu8
End music: "Floating" performed by the Early Birds (recorded in Eindhoven in 2000).
Did I forget to mention you above and are you a copyright owner? let me know and I will set it straight by linking to your original content in these credits.Making a monolithic telescope Part 3: Figuring & TestingHuygens Optics2022-06-10 | Use the following links if you want to skip to the next chapter of the video: 00:00 General intro 01:54 Required level of precision 07:12 Measuring surface shapes with interferometry 10:46 Fringe evaluation with DFTfringe 12:12 Optical Pitch polishing 17:19 Making molds using 3D printing 18:18 Results with variable surface tools 21:06 Primary mirror 22:20 Point Diffraction Interferometry (PDI) 26:48 Visual performance 29:58 NO MORE NAPS (featuring Dr. Fullersheit)
Links mentioned in the video: Website with the best and most detailed information on telescope optics: telescope-optics.net/. This is the direct link to the page about the different criteria and how they relate to aberrations: telescope-optics.net/effects1.htm
The 3D-printer used was manufactured by 3Bfab. More information on their products can be found on their website: 3bfab.com (not sponsored content - they did neither ask nor pay me to show their product)
Special thanks to Dr. Liam Fullersheit for his guest appearance. (;-).Making a Monolithic Telescope Part 2: Machining GlassHuygens Optics2022-04-18 | The second video in the series about manufacturing a small solid telescope. Time to make my hands dirty while doing artisanal stuff.
CONTENTS: 0:00 Intro 0:46 The monolithic version of the Cassegrain 2:23 About baffles and stray light 3:18 Drilling the glass core 6:00 Radius milling the glass surfaces 9:35 Calculating the Best Fit Sphere in Excel 13:52 Drilling baffles 14:23 Using spherometers 15:44 This Beat is Spherotronic 16:31 Rough / fine grinding 18:05 Optical Pitch polishing 20:43 What's next? 22:05 Looking through the uncorrected device 23:34 Thank you!
Windows program for calculating milling angle and evaluating spherometer readings: huygensoptics.com/assets/mirror_calculator_V01.zip Download and use at your own risk. Your virus scanner will probably evaluate this download carefully and scream murder and fire because it is a rarely occurring executable.
I used a few short clips from the following Youtube videos, assuming it is covered under "fair use" by placing references to the channels, and links to the corresponding videos in the description.
At 15:44, I made an 18 seconds remix of Technotronic's hit "Pump up the Jam". Please enjoy the original hit song by these Belgian techno pioneers: youtube.com/watch?v=9EcjWd-O4jI At 23:21: Shot take from Edmund Optics video "How an Aspheric Lens is Made": youtube.com/watch?v=CVDT3u1La6w
Did I forget to mention you here? Let me know and I will set things straight.Making a Monolithic Telescope Part 1: Optical Design and Aspherics.Huygens Optics2022-03-26 | 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 : patreon.com/huygens_optics
If you want to know more about the workflow in Zemax, the great tutorial videos by Scott Sparrold of OpticsRealm are a good start: youtube.com/user/opticsrealm/videos
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.
Did I forget to mention you here? Let me know and I will set things straight.Telescope Resolution vs. Aperture and WavelengthHuygens Optics2022-01-10 | Discussion about of the fundamental limitations imposed by aperture and wavelength on the maximum sharpness of a telescope. By discussing the energy mechanisms behind diffraction, I try to explain why this relationship exists. In the last part I discuss the implications for the recently launched James Webb telescope. Contents: 0:00 Intro 2:43 Short experiment with aperture 4:47 About angular resolution 7:44 Resolution comparison of 3 different telescopes 10:13 Diffraction phenomena explained using energy as a basis 14:08 Experiment showing edge diffraction in real aperture 17:14 The James Web resolution explained using aperture and wavelength
More about the background of the microscope experiment shown here is explained in this video: youtube.com/watch?v=TshYfYIxR9E
Electromagnetic theory taken from Fundamental University Physics, Part 2: Electromagnetism by Marcelo Alonso and Edward J. Finn
More information on the application of small telescopes can be found on the oresat.org website: http://oresat.org
Aberrator 3.0 is a software program written by Cor Berrevoets to simulate star-images in different telescopes. It can be downloaded from aberrator.astronomy.net
Where indicated, images from the NASA.gov website and Wikipedia.org were used.
Do you like what I do and want to support it? I'v recently started a patreon page: patreon.com/huygens_optics
REMARK: Huygens Optics has NO commercial ties with any of the products or companies featuring in this video. Everything shown is meant exclusively for educational purposes. Short third party clips are sometimes used, assuming fair use policy and always with a reference to the original source in the description. Did I forget you? Please let me know and I will set it straightMaking OLED DisplaysHuygens Optics2021-09-02 | Skip to 10:40 if you just want to see how they were made.
Contents: 0:00 Intro 1:29 First OLED: Tang and van Slyke 2:56 Polymer LEDs 4:25 Principle of the AlQ3 OLED 10:40 Let's make some OLEDs! 11:00 3D-printer photolithography 13:30 Physical Vapor Deposition (PVD) 15:52 Device operation 16:57 Black spot formation/degradation 18:50 Hermetic encapsulation
All technical details described in this video can currently be found in the public domain.
Video on the inventors of the OLED: "Pioneers of OLED: The Ching Wan Tang and Steven Van Slyke Story" youtube.com/watch?v=dbt8cGQPcpg
The original paper by Tang and van Slyke can be downloaded for $35 from: aip.scitation.org/doi/pdf/10.1063/1.98799. I did not do this, so I hope my memory served me well...
Other sources used (fair use policy assumed): Photo flexible OLED-display: pi-scale.eu Photo plasma display: "History of the Plasma Display Panel" by Larry F Weber, Photo Atari Lynx: boards.dingoonity.org/retro-gaming/atari-lynx-lcd-mod-by-mcwill Photo PVD: tekniker.es/en/pvd Did I forget anyone / objections? Please let me know and I'll set it straight.
ITO substrates can be bought from many different suppliers on Ebay.com, with widely varying prices. I bought mine (5 pieces) from seller "yaolihong2013" (no affiliation) because the same shop also sells Ytterbium.
The AlQ3 and TPD were both bought from TCI-chemicals (no affiliation).
The 3D-printer used for the photoresist exposures was a Phrozen Sonic Mini 4K. Avoid the new update (1.9) of the Chitubox-software supplied with this printer because it does not work properly. Version 1.8 or earlier does works correctly.
Photoresist used : AZ 4533 supplied by Microchemicals (no affiliation)
Do you like what I do and want to support it? I'v recently started a patreon page: patreon.com/huygens_opticsHow big is a visible photon?Huygens Optics2021-07-05 | This video is actually not about photon size but about coherence length. In this video I discuss the behavior of electromagnetic radiation, especially the aspect of interference. The experiment shows that there is no such thing as individual photons in EM radiation. The photon only exists as an energy exchange between radiation and matter.
0:00 General Intro 0:47 What do others say? 1:21 About wavelength and size 2:10 Interference in light 3:08 Electromagnetic waves and detection 5:25 Things that make you go Hmmm... 7:36 New experiment and setup 10:23 Calculation of single photon level (boring) 11:59 Result of the new experiment 12:41 Discussion of the result 16:29 About "shot noise" 17:16 EM field strength and probability of detection 19:18 So how big is it then? 20:02 Deleted scene
At 3:08 the Electric and Magnetic field components have been swapped accidentally.
Thanks to David Nadlinger, I was able to put my finger on what was experimentally wrong with the original experiment . The scientific explanation is actually very mathematical and way more complex: en.wikipedia.org/wiki/Degree_of_coherence. And although scientifically not very accurate, I tried to present a more intuitive description, based more on the classical description of EM waves rather than trying to explain the second order coherence function.
The "deleted scene" contains a 4 second clip of the movie "Crash Pad" (For preview see: youtube.com/watch?v=Pm0vmm8k0ks) It also contains a short audio clip of "New York City" by the Trammps (youtube.com/watch?v=XGmIDuraqNQ). I would also like to thank Vicky Pollard for explaining Quantization in more detail. These clips constitute copyrighted material, the use of which has not been specifically authorized by the copyright owner. The material serves as an educational and entertaining resource and only small portions of the original work are being used. This should constitute a 'fair use' of any such copyrighted material (referenced and provided for in section 107 of the US Copyright law).
If you wish to use any copyrighted material from this video for purposes of your own that go beyond 'fair use', you must obtain expressed permission from the copyright owner.17 U.S. Code § 107
Do you like what I do and want to support it? I'v recently started a patreon page: patreon.com/huygens_opticsDIY Physical Vapor Deposition (PVD) using Thermal EvaporationHuygens Optics2021-05-20 | This video discusses the building process of a system for doing Physical Vapor Deposition (PVD).
0:00 Intro 1:09 Thin film technology 1:56 Principle of PVD 3:22 Limitations of thermal evaporation 4:48 Thermal source construction 5:50 Required vacuum conditions 7:25 System layout and construction 9:25 Turbo screw up 10:25 Technical aspects 12:02 Plasma cleaning 14:02 Quick evaporation tests
Apart from some technical aspects of the machine, I also discuss the background of thermal evaporation as a technique to do PVD. The system will be used in the future to make small optical devices using photolithography.Etching small patterns in GlassHuygens Optics2021-02-23 | Contents: 0:00 Intro 1:00 On the risks of Hydrofluoric Acid 4:56 Buffered Oxide Etch (BOE) 6:06 Glass protection with Photoresist 7:17 Glass protection with Chromium 9:12 Laser Induced Etching (LIE, LIDE) 12:20 Smallest Tesla valves in the World. No, Universe! (As far as I can tell).
This video contains an overview of some glass etching experiments I did with Buffered Oxide Etch (HF / NH4F). Just for the record: the video is not meant as an encouragement to start experimenting with concentrated HF yourself. If the info in this video did not scare you off, please study the following webpage before proceeding. (Warning: page contains unpleasant graphics): emsworld.com/article/173379/hydrofluoric-acid-what-you-need-know
The video contains some images and clips taken from third party webpages and other Youtube channels. Please visit these to refer to the original content by clicking the links below. Did I forget anything? please let me know and I will set it straight.
The article below contains some good information on surface roughness introduced by etching osapublishing.org/oe/fulltext.cfm?uri=oe-27-8-10705&id=408193Making Optical Logic Gates using InterferenceHuygens Optics2021-01-16 | In this video I look into the idea of using optical interference to construct different kinds of logic gates, both from a conceptual- as well as from the practical perspective.
Contents 0:00 Intro 2:15 Logic gate operation 3:36 Optical logic gates 4:45 Concept of a diffractive logic gate 7:52 Practical aspects (photolithography and etching) 8:46 Wave front observation method 9:20 Results 13:51 Possible applications
The diffractive patterns were made by using a home-brewed windows Zone plate app and then modifying them further with photoshop. The Zone Plate app can be downloaded from: http://www.huygensoptics.com/assets/zp_writer.zip For Windows 10 and for personal use only. Virus scanners and Windows will nag about it being a rare / unknown file and make installation sometimes difficult. Sorry about that. Install this app at your own risk.
An overview article on various known optical logic gates can be found in this paper: hindawi.com/journals/aot/2014/275083 However it does not contain any mention of the configuration described in this video
The video contains references to detail videos on the following subjects: Photolithography: youtu.be/Lf-ev2Fop_k Chromium photomask etching: youtu.be/foMT8gLYxBY Other diffractive optics (photon sieves): youtu.be/TshYfYIxR9E Microscope viewing method: youtu.be/TshYfYIxR9EAnalog TV Equipment: R&S SFM test transmitter and CCVS video generator.Huygens Optics2020-12-16 | This video is a bit different from my previous videos and not related to optics. I made it purely out of interest for older (analog) equipment and technology. The video discusses the principles behind analog TV transmission technology, such as color encoding in composite video signals and RF transmission and modulation methods. For my demo I used a small TV set found in the street, a Rohde and Schwarz SFM test transmitter + CCVS video generator, and a Signalhound USB spectral analyzer.
Outline: 0:00 Wacko Christmas Intro 2:10 Equipment intro: CCVS generator + TV Test Transmitter 4:20 CRT screen viewed in slow motion 6:13 Monochrome composit video signal 8:26 Color composite video signal 12:36 Example of signal discussed 14:00 RGB-color conversion matrix 15:10 Rohde & Schwarz SFM TV Test Transmitter 17:29 Closer look at the transmission signal 21:15 The intermediate frequency explained 24:30 Extro
The following short clips were included in this video (under the fair use policy). Please check out the full videos to support creators, using the links below
@Technology Connection Youtube channel has made several excellent videos about analog TV technology. It discusses the subject more detailed and also from a different perspective (USA). youtube.com/playlist?list=PLv0jwu7G_DFUGEfwEl0uWduXGcRbT7Ran
Gavin of the Slomo Guys shows some REAL high-speed footage of a color TV screen How a TV Works in Slow Motion - The Slow Mo Guys youtube.com/watch?v=3BJU2drrtCM
Wikipedia contains pages on almost every specific subject discussed in this video. If you need more info then just search for the subject in Wikipedia. However, unfortunately most of the articles dive deep into the matter, which can be quite frustrating if you are not an expert. -----The Real Double Slit Experiment.Huygens Optics2020-10-05 | This video was edited 30-12-2022. I removed everything but the experimental parts of the original video. The reason for this is that I was no longer behind the way I explained the experiments, especially the quantum aspects.
In the video I show you how you can use a microscope to visualize the EM- wave propagation after light has passed the slits.
WARNING: do not attempt to repeat this experiment without using a camera! Looking at laser beams under a microscope with your bare eyes instead of a camera can kill your eyesight instantly and leave you blind for the rest of you life.Building a Small Cleanroom for Photolithography.Huygens Optics2020-09-17 | This video describes the design- and build process of a small cleanroom space for my workshop. In addition to facilitating working more cleanly, it also allows for working with dangerous substances, such as strong fuming acids, and can be used for processing photoresists. It's build from approx. 5m2 of trespa plate material and uses a HEPA filter and a fan to achieve a steady supply of clean air.
0:00 Introduction 0:47 Cleanroom classifications 2:10 Design considerations 4:33 Construction 7:10 Lighting conditions inside the cupboard 7:57 Air flow control 9:24 ConclusionFourier Optics used for Optical Pattern RecognitionHuygens Optics2020-07-25 | 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
Conversions of 2D images to 3D were done using Gwyddion. This very advanced piece of software is can be downloaded for free from: http://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_transformLight Waves Visualized using Photon Sieves.Huygens Optics2020-06-29 | The video shows how the optical wave front of a laser beam can be shaped by means of DIY photon sieves. It also shows how the quality and sharpness of the focal point in a diffraction pattern can be influenced by the number of diffractive apertures in the photon sieve surface.
Contents: 00:00 General intro 00:43 Photon sieves explained 04:21 Manufacturing of photon sieves 06:27 Photon sieve diffraction series 10:05 Time-resolved visualizations explained
Many thanks to Michal Miler for bringing the photon sieve to my attention.
The royalty free slo mo clip of the water wave at the end of the video could be displayed thanks to the video published on the Jim Quiter channel: youtube.com/watch?v=gS_tU6chC4AMaking a Mirror with a Variable Surface ShapeHuygens Optics2020-06-14 | Some concepts in this video have been pictured in a somewhat simplified manner to make it more accessible to a less specialized audience.
Contents: 00:00 General intro 00:56 Conic constant explained 10:00 Explanation of the manufacturing process 12:25 Testing the mirror 15:32 interferometric evaluation using DFTfringe
Additional info on clips/subjects featured in this video (in the order of appearance):
Clip of making the ellipse using a rope demonstrating constant path length is taken from the following video: youtube.com/watch?v=0maahsJQOJE
Astroforum link to 610mm flex mirror by forum user Firstlight (in Dutch): https://www.astroforum.nl/forum/instrumenten/zelfbouw-atm/1398665-61cm-flex-mijlpaaltje
With the interferometric tests I considered astigmatism in the mirror and only left the following zernike coefficients unticked: Piston X-tilt, Ytilt, Defocus, Xcoma, Ycoma.Making Tiny Fresnel Lenses during a PandemicHuygens Optics2020-04-05 | This video shows several types of micro-lenses that I made using a DIY maskless wafer stepper. The tiny lenses can for example be used for building a Shack-Hartmann wavefront detector.
YouTube does not like to redirect to this link. the file is (last part of the URL): /assets/zp_writer.zip
For Windows 10 and for personal use only. Virus scanners and Windows will nag about it being a rare / unknown file and make installation sometimes difficult. Sorry about that. Install this app at your own risk.
Reference for article on zone plate design: https://laser.physics.sunysb.edu/_pradyoth/Intel/Creating_dark_lines_in_space.pdf Wikipedia also explains this very clearly, but I just found this article first.
@ 0.34m: four happy seconds with Deodato, listen to the full song at: youtube.com/watch?v=l79248iHjwIMaskless Wafer Stepper Part 3: Electronics and Software.Huygens Optics2020-02-10 | This is the third (and final) video on the DIY maskless wafer stepper project. It discusses the electronics and software.
0:00 General intro 0:49 Wafer stepper system overview 1:48 Dynomotion KFlop controller card 2:42 Wafer stepper control electronics 6:32 Digital wafer stepper software
I tried to build it from very cheap components, most of which I bought second hand on Ebay. I also used an Arduino Due and a KFLOP CNC card from Dynomotion to control the movements and used Microsoft Visual Studio for programming the code.
If you are new to the project you might want to check out the previous two video's first:
This video shortly features one of the art pieces of the dutch graphic artist Maurits Cornelis Escher. I'm only using this picture to demonstrate the principle o image stitching as it is used in my software and not for any commercial applications. If you are interested, please visit the Escher foundation and take a look at his fascinating work: mcescher.com/nl/stichtingMicro Lenses made with Photolithography.Huygens Optics2020-02-06 | 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: youtube.com/watch?v=ETx_fjM5pms
It is now possible to contribute financially to the Huygens Optics Youtube channel. Please refer to the "About"-page of the channel for details.Maskless Wafer Stepper Part 2: MechanicsHuygens Optics2020-01-25 | This video is the 2nd of 3 video's on the design and build process of a small maskless wafer stepper. It discusses the mechanical aspects of the machine, in particular the challenges that I face to achieve the requirements.
0:00 General intro 1:18 First devices (Fresnel zone plates) 3:28 Mechanical system (wafer stage / focusser) 7:49 Position and lead screw linearity 10:09 Determining straightness and perpendicularity (squareness) 11:45 Z-axis positioning using a piezo actuator
I also show some crude footage of the first optically active devices. Sorry about the image quality, I will get back with more detailed images in future videos. The idea is to make micro optics with this machine.
The end of this video contains a short clip from the rock-mockumentary "Spinal Tap" at 13:41. If you want to know why it is important to have controllers going all the way up to 11 in your equipment, please see the original video clip: youtube.com/watch?v=4xgx4k83zzcMaskless Wafer Stepper Part1: OpticsHuygens Optics2020-01-04 | I've 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 video's 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 I'm still in the building process of the machine and the software.
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.How to make Very Flat Optical Surfaces on GlassHuygens Optics2019-12-16 | The video shows (hands on) how a nanometer level flat optical surface can be made. It first discusses the principle of the continuous pitch polisher, also known as the planetary polisher or optical lap master.
00:00 Intro of flat surface creation / polishing 00:37 Optical flatness specs compared to general machining results 01:04 Angular machine / continuous pitch polisher explained 07:24 Simplified version of the continuous pitch polisher 10:15 CNC polishing machine construction explained 11:16 Example of polishing 3 objects flat on a plate
In addition, I discuss my personal method to make flat optics which is a modified / simplified version of the continuous pitch polisher.
This video contains short clips of other videos showing similar continuous pitch polishers in action.
Clip at 1:20 taken from Gijs Loning's video (OpPad) on his visit to the Zeiss Factory: youtube.com/watch?v=9YhsTEOjxtU (very nice and informative video, Dutch spoken)Metal Detector Discrimination Explained (with a Garret AT Pro)Huygens Optics2019-11-12 | In this video I discuss the principle of a VLF- type induction balanced metal detector (Garrett AT pro), in particular how the discrimination between different metals works. I do this by looking at the emitted and received signals of a test coil, so not by opening up the detector.
00:00 General Intro 00:34 Need for discrimination / ID in metal detection 03:19 Test setup 03:55 Principle of double D coil explained 08:29 ID and phase shift for different metals (para- and diamagnetism)
It turns out that the detector measures the phase delay between the emission and reception coil. The reception coil shows this delay because of changes in the inductance which are introduced by the conductivity and intrinsic magnetic properties of metal objects in the vicinity.Next Level Spirit Level (for billiard / pool table)Huygens Optics2019-10-14 | Leveling a billiard table to an exact horizontal orientation requires a very accurate "spirit level" device (also called "bubble level"). In this video I show the complete process, from requirements and design, to prototype manufacturing of the bubble level from 2 borosilicate glass disks.
If you need more details on how to make a spherical surface, you might want to check out this previous video:
The two video's referred to below show the optical contact bonding process in detail, so make sure you check them out. It is quite impressive to see 2 surfaces melt together spontaneously by just atomic forces at the surface:
"Fabrication Methods for Precision Optics" by Hank H. Karow contains detailed information on how to build and operate an angular machine, for those of you interested in building one.Optical Lens Centering using a LOH LZ-80.Huygens Optics2019-10-08 | This video discussed the theoretical- and practical aspects of lens centering. The video features a lens triplet from the telescope corrector .
Unfortunately it turned out that -after my Loh LZ-80 centering machine was brought back to operational status- the lenses were already correctly centered. The cause for their poor performance was actually in the construction of the optical tube holding the triplet. So in the end, centering of the lenses turned out to be unnescessary.