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Minimum focus point size with Aixis

oic0

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I was just wondering if anyone has done any minimum focus point tests with different wavelengths / diodes using the common Aixis module and collimating lens as the focusing device (just for apples to apples comparison)?
I remember people saying how tight the 405s can get. I know my 445 makes lines as small as a ball point pen in plastic when properly focused. Does the 405 go even tighter? what about 650 etc...? Also what about DPSS? my cheap lil green pen already puts needle size holes in things focused out to infinity.

I just want to understand what the limits of focusing are so I have a better understanding of how the different commonly available frequencies compare to each other.
 

udanis

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I was just wondering if anyone has done any minimum focus point tests with different wavelengths / diodes using the common Aixis module and collimating lens as the focusing device (just for apples to apples comparison)?
I remember people saying how tight the 405s can get. I know my 445 makes lines as small as a ball point pen in plastic when properly focused. Does the 405 go even tighter? what about 650 etc...? Also what about DPSS? my cheap lil green pen already puts needle size holes in things focused out to infinity.

I just want to understand what the limits of focusing are so I have a better understanding of how the different commonly available frequencies compare to each other.
You can really focus to a point a small as your physically able to do, that's just the way lenses work. You can make it as fine as you want pending you can visually see how small it is and have precise enough motor control of your finger to adjust the lens. Does that make sense? lol
 

qumefox

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theoretically the smallest the beam waist can get is the length of the wavelength your using with a TEM00 beam.

In actuality, it depends on your optics, the mode of the beam your focusing, etc. When dealing with non-guassian beams, different points of the beam are going to focus at different rates, which means you won't have a 'singular' focal point, which limits your smallest dot size. The less the optics distort the beam, and the closer to TEM00 the beam is, the smaller the focal point you can get.
 
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