Hello.
Some times ago I have bought some Laserglow Beam Expanders.
Those expanders are originally made for the Hercules 532 nm series, so I was forced to unmount, decoated and recoated the three lenses for the 445 nm 9mm diode.
Then I have adapted the expander to use with the dear old Jayrob Frankenstein kit.
The biggest problem was to find a correct input beam size and the right input divergence, since the LG beam expander do not allow input beams bigger than 2 mm.
In my Frankenstein kit I use 405-G2 lens to collimate the beam. Most of the work was to find the correct input beam: a too large input beam line will cause a loss of power, since part of the line will be truncated by the small diameter of the input lens, while a too small imput beam line will create an undersized input beam, that cause damage to the coating of the first lens and noticeable reduction of the expander field (I.E.: nearest focal point too far from the beam expander aperture). Besides this, another big problem was the up/down, left/right centering of the beam: any little error cause truncated line and so a noticeable loss of power. But at the end of all the attempts, I have obtained a perfect beam field range, centered, powerfull, and with an acceptable loss of power (about 10% less of the initial value). Unluckly the decoating procedure of the lenses caused some damage to the structure of the glass itself (the lenses are boiled for several hours in a solution of hydrochloric acid at 212 F), so the lenses were not perfect as the original condition. Probably a virgin lenses set will have less loss of power. I have all the parameters of the LG beam expander lenses, but I was unable to find identical lenses from the major optical companies like Edmund Optics.
Now I'm working in a hybrid beam expander (half LG and half Jetlaser) for the Zaser (custom XL prototype) with the 3.5W new Nichia diode, and in a special 10x beam expander from CNI that allow an input beam size of 4-10 mm, ideal for example for the red diodes with wide output lines. This modified beam expander will be mounted in the Red Stubby C-Mount project from Jayrob, but both my projects are stopped because Angelos (Lazeerer) is disappeared again from the forum since 45 days, and he has my new red diode and hopefully his long awaited 4A driver, suitable for the 4W c-mount red diode and for the 3.5W 445 nm Nichia diode.
If You need some other infos I'm here :beer:
