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ArcticMyst Security by Avery

Can any green cheap achieve divergence level of OLD RED DILDA?

Joined
Feb 15, 2010
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Hello.

I have just received my 200mw old style red dilda and after testing burning capabilities (great but I don't look for it) I have tested the laser focused to infinite and I have been amazed with the dot size at long distance. It is the smaller I have seen between several green cheap lasers.

I own a kaleidoskopic 200mw green pointer and its beam is great but the dot diverges quite a lot at long distance.

I have got a <200mw focusable green torch and it can't beat the small dot size that dilda performs.

Is there any cheap green with the divergence level of the red dilda??
 





Joined
Nov 7, 2008
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It's very unlikely that you'll see any cheap green DPSS lasers with divergence as low as can be routinely had using most common diodes.. The reason is a bit complex, but it has to do with the fact that the beam from a laser diode gets expanded many times before it even reaches the output lens since it origintes from a microscopic point source. Since divergence is inversely proportional to beam diameter (larger diameter=smaller divergence angle) this expansion allows for very small divergence angles. In contrast, with most cheap DPSS lasers the beam does not originate from a point source, which means the beam has not been expanded so many times before collimation, resulting in higher divergence angles.

Divergence is also linked to cavity length (longer cavity=smaller divergence angle) and both cheap DPSS and diodes have very short cavities, diodes being on the order of <2-3mm in many cases. This is why a bare diode with no lens has such high divergence that it could be compared to a flashlight in terms of beam shape.
 




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