When I found that the wavefront of the image surface of Cassegrain-type Ritchey Chretien telescope to have a hole in the center (as shown below) , I wonder how it is formed.
Thanks a lot if anyone can explain it !
Best answer by David.Nguyen
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+2
Hi DDDD,
I’m not exactly sure without seeing your system in more details, but typically, the secondary mirror obscure the central portion of the incoming ray pencil. Thus creating a “hole” in the wavefront.
Perhaps this picture from Vladimir Sacek (found on his website) can help:
Ignore the text, just look at the beam path in yellow. Do you notice the missing cone after the secondary mirror? This is why the wavefront can’t be calculated.
I hope this helps.
Take care,
David
Hi DDDD,
I’m not exactly sure without seeing your system in more details, but typically, the secondary mirror obscure the central portion of the incoming ray pencil. Thus creating a “hole” in the wavefront.
Perhaps this picture from Vladimir Sacek (found on his website) can help:
Ignore the text, just look at the beam path in yellow. Do you notice the missing cone after the secondary mirror? This is why the wavefront can’t be calculated.
I hope this helps.
Take care,
David
Hi David :
Thanks for your help !
Hi DDDD,
I’m not exactly sure without seeing your system in more details, but typically, the secondary mirror obscure the central portion of the incoming ray pencil. Thus creating a “hole” in the wavefront.
Perhaps this picture from Vladimir Sacek (found on his website) can help:
Ignore the text, just look at the beam path in yellow. Do you notice the missing cone after the secondary mirror? This is why the wavefront can’t be calculated.
I hope this helps.
Take care,
David
Hi David :
I have some further questions , hoping that you may help.
I now need two telescope to intefere ,I expect the result to have no hole in the center.
I think after the process of focusing , the result should be a point, the wavefront should have no “hole”. But the result seems to have a “hole” in the center.
Sincerely
DDDD
This is the file I used.
+2
Hi DDDD,
You need to give us more details about what you are trying to achieve. I downloaded your file, but there’s only one telescope in it, as far as I can tell.
Let me know if I’m overlooking something.
Take care,
David
Hi DDDD,
You need to give us more details about what you are trying to achieve. I downloaded your file, but there’s only one telescope in it, as far as I can tell.
Let me know if I’m overlooking something.
Take care,
David
Hi David :
The result after intefering should have no “hole”. I used the inteference formula to get the inteference result of two identical focused wavefronts but it has “hole” so I am confused.(So I just used one zmx file as shown above.)
Sincerely
DDDD
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