@HuygensOptics

@HuygensOptics

Huygens Optics | Coherence in star light @HuygensOptics | Uploaded January 2024 | Updated October 2024, 1 hour ago.
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.

Simulations were created using the python code supplied by @DiffractionLimited
The simulation image file can be downloaded from:
huygensoptics.com/2D_wave_sims/telescope_incoherent_light.png

Milky Way picture by Philippe Donn

#short #light #physics #optics

$Coherence in star light This short discusses (very briefly) the difference between temporal and spatial incoherence. It also contains a wave animation of a telescope mirror that concentrates a field on a sensor. Of those of you who want to know more about coherence I made these videos: Temporal coherence: https://www.youtube.com/watch?v=dtcq5b0R65w Spatial coherence: https://www.youtube.com/watch?v=nba4ztLBEh0 Presented here are 2D-animations of a field, which means that the intensity of the focused light at the sensor increases with the diameter of the mirror. In a 3D scenario however, the intensity increases with the square of the diameter of the mirror, leading to a much larger difference between the incoming and focused radiation intensity. Simulations were created using the python code supplied by @DiffractionLimited The simulation image file can be downloaded from: https://huygensoptics.com/2D_wave_sims/telescope_incoherent_light.png Milky Way picture by Philippe Donn #short #light #physics #optics$

The double beam experiment

How big is a visible photon?

$How a Lens creates an Image. 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 A list of links to subjects mentioned in the video: Nils Berglunds Channel: https://www.youtube.com/c/nilsberglund Link to the full NA video by Nils: https://www.youtube.com/watch?v=RbojFORps98 Making Fresnel Zone plates: https://www.youtube.com/watch?v=uf3Y0-6NbjQ Building a Maskless Wafer Stepper: https://www.youtube.com/watch?v w0Z2Y5vaAQ&t=343s 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.$ $Micro Lenses made with Photolithography. Im quite excited to show you the focal properties of my microscopically small lenses that I made using photolithography. These lenses are actually Fresnel zone plates which use diffraction as the method for focussing the light. They were made using the DIY maskless wafer stepper. The lenses have more than one focal plane, and you can easily observe the 1st, 2nd and 3rd order focal planes when they are used in combination with monochromatic light sources. I used a static image from a video on meta surfaces. Please check out this video if you want to know more about this subject: https://www.youtube.com/watch?v=ETx_fjM5pms It is now possible to contribute financially to the Huygens Optics Youtube channel. Please refer to the About-page of the channel for details.$ $Light Waves Visualized using Photon Sieves. The video shows how the optical wave front of a laser beam can be shaped by means of DIY photon sieves. It also shows how the quality and sharpness of the focal point in a diffraction pattern can be influenced by the number of diffractive apertures in the photon sieve surface. Contents: 00:00 General intro 00:43 Photon sieves explained 04:21 Manufacturing of photon sieves 06:27 Photon sieve diffraction series 10:05 Time-resolved visualizations explained Many thanks to Michal Miler for bringing the photon sieve to my attention. Reference to the article on achromatic photon sieves by Chiongxi Zhou:https://www.researchgate.net/publication/24192201_Experimental_study_of_a_multiwavelength_photon_sieve_designed_by_random-area-divided_approach More on the maskless wafer stepper project (link to playlist) : https://www.youtube.com/playlist?list=PLaLGh7vzNIRRuvbxZKHOUaeosIO4hpcsw If you are interested in maskless wafer steppers or how to build one yourself, make sure you check out this great video by Sam Zeloof as well: https://www.youtube.com/watch?v=Nxz_ENnmgtI The royalty free slo mo clip of the water wave at the end of the video could be displayed thanks to the video published on the Jim Quiter channel: https://www.youtube.com/watch?v=gS_tU6chC4A$ $Incoherent Wave Emitter This simulation shows a spatially- and temporally incoherent wave emitter that consists of around 100 individual wave sources. The sources are continuous but all have a slightly different emission wavelength. This results is the emission field and intensity distributions shown in the video. The simulation was made using a python script supplied by @DiffractionLimited The image files for the simulation can be downloaded here: https://huygensoptics.com/2D_wave_sims/non_coherent_emitter.png #physics #light #short$ $Gradient Index Lens Explained This is short is about how a Gradient Index Lens (or GRIN lens) works compared to how a normal confocal lens with curved glass interfaces operates. The diffraction inside the lens is probably due to the fact that the refractive index gradient is not exactly correct. The total gradient is approximated from 5 linear gradients instead of 1 smooth circular gradient. This is probably the reason for the observed interference pattern observed. The simulations were made using the code supplied by @DiffractionLimited Music: Nebular Focus by Dan Henig #optics #light #physics$

Making a Mirror with a Variable Surface Shape

Fourier Optics used for Optical Pattern Recognition

Optical Lens Centering using a LOH LZ-80.

Curve Generation using a Milling Machine (Short Impression)

Coherence in star light @HuygensOptics