still no one gave the answers to the questions asked!!!!
Hey guys I've been poking around looking at different lenses for lasers but I haven't really found any info on the differences between a glass ball lens and the g2, 3, 7 etc lenses. When it comes to divergence and power, how does the glass ball lens compare to the g2, g7 and 3 element lens? I've also heard that removing the gball could lessen the life of the laser? Is that true and why?
Removing the GBall lens from multi watt blues will shorten the lifespan., I had read about why some researchers think this happens and it's basically exposure to the air/contaminants/humidity and micro cracks that develop on the facet as well as facet damage from reactions with air/humidity as well as a possible build up on the facet from product with air while lasing.
If you search you should be able to find other threads where I posted a link to the research, I don't have the link at hand.
The GBall lens appears to be very efficient ( about 95% ) but they appear to not all be the same from what I have seen, for example some blocks of nubm06 with the GBall lens cans will be pretty close to focused making a small spot on the wall 10 feet away while another block of nubm06 with what looks like the same GBall lens and can ( same can length ) will not be focused much at all making a large spot on the wall, I expect this is because of a different lens grind/shape and I would think that the OEM would order blocks with the focus they want for their device, or placement in the can and/or the thickness of the indium foil that bonds the can to the diode could be of varying thickness.
I have shortened the GBall can and placed the lens into a threaded barrel so I could focus a diode with the lens and it was not giving me the tight beam waist that we can get with our other lenses, I'm not sure why as I break them when attempting to remove from their cans, I don't think they are very useful for our purposes but if you find otherwise please do share. I think Badboybilly said he had used one in a threaded barrel and it was nothing special, but again I don't think they are all the same so it's possible that one example may work better than another, I have not had any luck reusing them once removed.
G2 is a single element aspheric broadban coated short focal length, divergence is not as good far field because of it's short focal length but up close it's the best for home CNC or for use pre beam shaping optics. It passes the most power and is the LPM testing lens of choice. Passes about 95%
G3 Similar to G8 but a smaller diameter lens in a regular size M9x0.5 lens barrel with a smaller opening, it passes less power than the G8, about the same as a 3 element but is cleaner than 3 element, it's a single element long focal length broadband coated. Passes about 70%
3 element is a multi element with good divergence but some clipping and the most power loss of the glass lenses. Passes about 70%
G7 is a single element long focal length making divergence good but not as good as the 3 element or G8 and the lens is pressed/glued in making it a trouble prone lens. Passes about 85%
G8 everything the G7 was supposed to be and then some, my new favorite, it's a single element broadband coated long focal length with the best divergence. Passes about 90%
