635nm correction optics GB

[Fenechlaser]

I
However that distance will be shorter with the new concave lens.

I'm confused now. What is this GB for, a convex or a concave lens (obviously paired with the larger cylindrical lens?

[CDBEAM]

BHW...First....always use the search feature. Many times...even reviewing what has been posted will help you to focus your questions for your further understanding !! Some threads are very, very long....but you must dig thru....and you will always learn !!See post # 31 and # 35 in this thread. They have drawings of the general arrangment and how to hold the cylinderical lenses. This is ONE way to do things...there are others.

Furthermore... For a noob...Lets say we call the two LD’s…LD1 and LD2. The beam from LD2 travels out of the Collimation lens….and hits the Knife edge mirror and takes a 90 degree bounce. From there the beam travels to the first C-Lens for correction.
The beam from LD1 travels thru the Collimation lens…and just clears over the top of the knife edge mirror…and continues on to enter the first C-Lens. The beams of LD1+LD2 join up at the knife edge plane…the beam from LD1 lays atop the beam from LD2…like a “ Double Decker Bus”

The 4mm wide x 2mm tall geometry lends itself perfectly to this “Vertical Stacking “ arrangement. With one beam laid atop the other beam…you end up with a 4mm x 4mm geometry entering the C-Lenses....

The C-Lenses ( Cylinderical Lenses) optically correct the ML520G71 LD beam....which we are trying to use...even though this laser diode was NOT designed for use in a projector application. The ML520G71 has a very astigmatic output ( wide spreading beam )...but is a very powerful and has a desireable wavelength. It is also relatively inexpensive !!

Generally speakings....optical pathways demand one element be perpendicular to another....so....lenses MUST be at 90 degree to the beam axis...otherwise...you will get distorted geometries. You cannot have things..." not true "...it will not work !!!

Also...you will find that most of us here....are not Optical Engineers....or Laser Engineers....But...we ALL share a great spirit of enjoyment in the hobby....and I am constantly learning more. Keep reading....and you will learn too !! BEAM

Fenechlaser...Both lenses are Plano-Convex...flat one side...outward curve on the other side...see post # 35 for the orientation.

[bhwollen]

Holy crap, I've been reading for 4 and a half hours and I'm on page 19....

[kiyoukan]

Well right now cd beam im getting info for the concave lens, to replace the first convex.
The reason being is space. there is no need for the lenses to both be convex and have that point in the center as my tests showed that setup cant work.
This will shorten the distance a bit and make it take up less space.
Both will work just fine.

People were asking me if it could be made shorter as they did not want to dedicate that much room to correction optics.

[bhwollen]

Kiyoukan. Do you still have those 20k galvos for sale?

[kiyoukan]

no they were removed from tha sale thread due to the fact that i used the y galvo in my harp.
if you want just the x galvo plus amp no psu i can sell you that.

[steve-o]

Holy crap, I've been reading for 4 and a half hours and I'm on page 19....

lol Congratz, you're almost half-way thru! Better than most people can do !!

[bhwollen]

I'm on 26 now.

[steve-o]

Well done Bh. You are well on your way to earning the Photonic Wings of the Red Grail. Only those who read these sacred scripts will truly understand the way of the Six-Thirty-Eight Coherent Beam

[bhwollen]

Just read that entire thread. Wow...

Updated list of what I want from this group buy.

1 set of C-lens $40
4 dave lens $37 x 4 = $148
10 mounts $9 x 19 = $90
Total= $278. Shit. I need to save up some money.

I assume we will get up to 100 mounts before 50 of the others so I will plan for the lower price.