G2, G8 and 3E lenses

[CoolLaserUser]

Hello guys!

There are loads of different laser lenses that anyone can purchase, each has different characteristics for the output, divergence and etc.

I have heard a reputation and seen that G8 lenses tend to sit far away from the diode to make the laser beam tight (unfocused), and for focusing/burning you turn the lens anti-clockwise which will make it sit even further away from the laser diode.

My question is that is it also the same for G2 and 3E lenses, or do they sit closer to the diode for making the laser dot as small as possible for long distances?

Thanks

 

[RedCowboy]

There have been tons of posts on these lenses.

G2 is a single element glass short focal length lens vis ar coated 400-700nm range, rear fl is 2.39mm.

G8 is also single element glass long focal length vis ar coated 400-700nm range, effective focal length is about 8mm.

The 3E lenses are multi element glass and range in focal length from about 4-5mm, they are individually ar coated for red, green and blue often denoted as 3ER, 3EG and 3EB although dtr did have some broadband 3e lenses made once upon a time, but I don't think they are available today.

G2 is the most efficient as it is least likely to clip the edges of our multi mode beams, but being short fl is best suited for up close use.
3E lenses are the least efficient of the lenses mentioned and are most prone to clipping which is more profound with higher divergence laser diodes, however they do work pretty well with fac enhanced laser diodes.

 

[CoolLaserUser]

Thank you for answer and good information @RedCowboy