All Questions
30
questions
0
votes
1
answer
129
views
Intensity of central maximum for a diffraction grating
If I send a typical 5 mW, 532 nm laser pointer beam through a diffraction grating (~1,000 slits/mm), then I'd expect the beam to cover something like ~1,000 slits. The resulting intensity of the ...
- 303
11
votes
1
answer
276
views
Unexpected laser pattern through calcite crystal
I've bought a calcite crystal and tried to see birefringence by shining a laser through it.
I get a split spot in the centre of a sixfold pattern
The hexagonal pattern resembles a diffraction pattern,...
- 528
2
votes
0
answers
47
views
Is it possible to measure the temperature of a candle by the diffraction method?
I am reading a book " Physics, Fun and Beyond" by Eduardo de Campos Valadares. In his book, he is mentioning about an experiment "bending laser beams with hot air." I am posting a ...
- 221
1
vote
1
answer
112
views
Diffraction of a laser composed of 2 monochromatic colours through a single slit / $N$ slits
To make the example simple, let's say we have a yellow laser that is the combination of 2 monochromatic lasers (green + red). In the example I will give, let's consider that the slits are narrow ...
- 197
2
votes
6
answers
431
views
What is the principle behind diffraction?
If we shine a green laser on a wall in a dark environment, we would observe a bright dot in the middle. Now, if we fix a grating just in front of where the laser is held, when the beam strikes the ...
- 121
0
votes
0
answers
98
views
"Loss" around the transmitting window of a laser cavity due to diffraction?
Take a laser cavity consisting of a gain medium, a totally reflecting mirror, and a partially transmitting window:
(https://www.researchgate.net/figure/Laser-cavity-composed-of-a-gain-medium-in-...
- 899
0
votes
1
answer
442
views
DIY Experiment fiasco: Single slit laser pointer already showing interference pattern
I tried to run the double slit experiment at home for my kid with a cheap red laser pointer. I partially covered the laser with four pieces of electrical tape to make a tiny square hole. To my ...
- 103
0
votes
0
answers
29
views
Generation of an beam with an arbitrary initial profile
Is it possible to generate a beam with an arbitrary initial profile? For example, the finite Airy beam has an initial profile $$\phi(s,0)=exp(\alpha s)Ai(s).$$
In practice, this finite Airy beam is ...
- 21
2
votes
0
answers
87
views
Holograms as a superposition of many individual interference patterns
I've recently started reading about non-linear optics and holograms. While I do understand the basics of how holograms are made, by superposing the reference waveform on the object waveform over a ...
- 1,791
0
votes
2
answers
125
views
Effect of a cylindrical lens in front of a diffractive optical element (DOE) and 5mW red laser
I want to expand the image formed by a grid pattern diffractive optical element (DOE). I will be using a 5mW red (650nm) laser. I thought maybe putting a cylindrical lens in front might spread the ...
- 3
1
vote
5
answers
2k
views
How does diffraction cause laser beam divergence, and why will a laser beam always diverge, due to diffraction?
I have seen it said that diffraction causes laser beam divergence, or that a laser beam will always diverge, due to diffraction, or some variation of these statements. I understand diffraction in ...
- 899
1
vote
0
answers
35
views
"Anomalous" Interference Maxima from a Diffraction Grating
When shining a red diode laser ($\lambda = 635$ nm) laser through a diffraction grating (5276 lines/cm), I'm observing what I consider to be anomalous maxima near each of the expected maxima for the ...
- 758
0
votes
2
answers
1k
views
Spatial Light Modulator (SLM) phase-only versus amplitude-only modulation
I am reading about the phase-only vs amplitude-only modulation with Spatial Light Modulators (SLMs). I wonder if there are specialists here who do this for living.
For instance, here the authors ...
- 1,184
1
vote
3
answers
418
views
How does light emitted by a laser diode not get diffracted as it leaves the surface of the emitter?
In a stacked laser diode array, multiple beams are emitted parallel to each other. These beams can be very close to each other, which should results in interference patterns. How does this setup ...
- 23
0
votes
1
answer
60
views
Colored fringes in optics
What optics principle is responsible for the colored fringes seen in the attached picture?strands of hair reflecting sunlight when held very close to the lens[]1]1
- 1