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Light & Coherence part 1: Temporal Coherence

Huygens Optics
163K subscribers
122K views 2 years ago
This is the first episode about coherence and how this wave phenomenon can cause waves to behave like localized entities. Unfortunately the quantum (or corpuscular) description of light leads to a lot of confusion. The goal of this video is to describe "quantized" behavior of light purely from wave principles. 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 Link to the referenced Physics Explained video:    • What is the Heisenberg Uncertainty Princip...   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  …...more
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Intro

0:00

Historical perspective

1:04

Quantization and the photoelectric effect

2:58

Light is just waves

6:42

Coherence explained

7:24

Temporal coherence as a sum of EM-fields

12:54

Coherence length vs. spectral band width

16:47

experiments on the coherence length of light

20:25

A sharp viewer noted that there is an error in the formula on the sheet at.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.

27:25
Light & Coherence part 1: Temporal Coherence
6KLikes
122,209Views
2023Feb 7
This is the first episode about coherence and how this wave phenomenon can cause waves to behave like localized entities. Unfortunately the quantum (or corpuscular) description of light leads to a lot of confusion. The goal of this video is to describe "quantized" behavior of light purely from wave principles. 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 Link to the referenced Physics Explained video:    • What is the Heisenberg Uncertainty Princip...   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    / veritasium   ‪@upandatom‬ ‪@ProfessorDaveExplains‬    / lookingglassuniverse   Did I forget anyone? Please let me know and I'll set things straight. End music: Floating; The Early Birds. © JJM Vleggaar, 1999

Follow along using the transcript.

Huygens Optics

163K subscribers