<p>I'm not sure how to define the "edges" or obscurations in a case of gravitational lensing.  The image we produce on Earth is the combination of our local telescope lens elements and the "grav lens" a zillion Kessel Runs away from us.  Even if you use the premise that the black hole itself is a central obscuration which should cause a Spot of Arago, I don't think any other diffraction-like effect is observable from such a great distance.  All the wavefronts of  light which passes thru the GravLens region continue to expand, ending up near-parallel from Earth's viewpoint. </p>

CC BY-SA 4.0
2018-05-07T17:10:12.630Z
2018-05-07T17:10:12.630Z
Carl Witthoft
<p>As far as I understand the wave-optics effects,such e.g.diffraction at a caustic, are hardly observable in the gravitational lensing. Are there any observations where the diffraction paterns of the visible light have been seen? If not visible, which wavelength?</p>

CC BY-SA 4.0
2018-05-06T20:36:42.610Z
Where are you expecting to see diffraction?
ProfRob
CC BY-SA 4.0
2018-05-07T06:20:08.737Z
The inclusion of the word "caustic" suggests http://iopscience.iop.org/article/10.1086/376896/fulltext/57273.text.html is relevant
James K
CC BY-SA 4.0
2018-05-08T16:32:23.100Z
I meant: Is something like that is observed in visible light https://arxiv.org/pdf/1207.4034.pdf
Truffaldino
<gravitational-lensing>
Is Diffraction of light observed in gravitational lensing/microlensing?
Truffaldino
# Is Diffraction of light observed in gravitational lensing/microlensing?

(Asked by: username_0 on 2018-05-06)

As far as I understand the wave-optics effects,such e.g.diffraction at a caustic, are hardly observable in the gravitational lensing. Are there any observations where the diffraction paterns of the visible light have been seen? If not visible, which wavelength?

**Tags:** gravitational-lensing
> **Comments:**
> **username_1**: Where are you expecting to see diffraction?  
> **username_2**: The inclusion of the word "caustic" suggests http://iopscience.iop.org/article/10.1086/376896/fulltext/57273.text.html is relevant  
> **username_0**: I meant: Is something like that is observed in visible light https://arxiv.org/pdf/1207.4034.pdf  

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## 1 answers

### Answer by username_3 on 2018-05-07. Score: 1

I'm not sure how to define the "edges" or obscurations in a case of gravitational lensing. The image we produce on Earth is the combination of our local telescope lens elements and the "grav lens" a zillion Kessel Runs away from us. Even if you use the premise that the black hole itself is a central obscuration which should cause a Spot of Arago, I don't think any other diffraction-like effect is observable from such a great distance. All the wavefronts of light which passes thru the GravLens region continue to expand, ending up near-parallel from Earth's viewpoint.


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