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Hello, 

 

New user and first post here. I am trying to collimate a beam coming from a fiber with 0,26 NA, 4,5 nm and apodization of 1.0 in order to have a 6 mm diameter beam along the maximum possible distance (desired between 2-3 meters). 

I did it using lenses but now I want to try with an OAP from Thorlabs. This is the model used:

 

 

For achieving my goal I think I have to inverse the mirror so the image shown in the picture acts like my source, but I have tried with coordinate breaks and I can not manage to do it. Once I have done it I have to optimize the position of my source using those operands in order to achieve the desired width of the beam right?

 


Thanks for your help

This Knowledgebase article may be of help: Demystifying the off-axis parabolic mirror

The collimated Gaussian beam size will be dictated by the source point apodization and the focal length of the OAP.

Regards,

Jeff


This Knowledgebase article may be of help: Demystifying the off-axis parabolic mirror

The collimated Gaussian beam size will be dictated by the source point apodization and the focal length of the OAP.

Regards,

Jeff

 

Hello Jeff the thing is that I have followed all the steps from that article but I don't know where does it takes in account the desired beam width and how to manage that in my system, because all the inputs that article uses for the lens data are from the OAP's supplier. In my case I want a beam width of 6 mm and after doing all of this I have a 16 mm beam width


@Bozkov:

The Thorlabs website explains how the collimated beam diameter is related to the OAP focal length.

 

The reflected focal length is shown here:

 

For an NA = 0.26 and a target beam diameter of 6.0 mm, the RFL should be ~11.5 mm.  It looks like the shortest focal length OAP that Thorlabs sells is 15 mm, which yields a beam diameter of ~7.8 mm.  Edmund Optics sells one with a focal length of 12.7 mm (6.6 mm beam diameter).  You could obviously look at other potential suppliers as well.

Regards,

Jeff


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