Mitsubishi ML520G71...Red Holy Grail or Flashlight Fail ??

[kiyoukan]

Interesting idea about the placement there.
Yeah mine are 6x not 8x.
one problem i see it can be very hard to get super close to the diode lens if you are stacking vertically.
My thought would be if you had an 8x setup but wanted to stack that extra distance would make your beam larger than 4.5mm and no real way to make it smaller.
You might be right in that the distance of the correction optics may worsen the spot characteristic by a slight margin, but i would think it is very minor.
And the added benefit to be able to chose the beam size just by sliding the laser closer and farther is very nice.
You can go from a 3.4mm to a 4.5mm and that gives alot of ranges for people with different scanner mirrors.
Tho this distance will change the divergence from a 1.2mRad down to a 0.82mRad

I kinda had the idea to build the correction optics on a solid tray that could slide 10mm farther or close to the diode, this would allow someone to loosen 2 screws and just adjust the distance without the hassle of having to re align the optics.
This would allow someone that upgraded from 5mm mirrors to 6mm to quickly change the beam characteristics.

[steve-o]

^ Nice idea.
Anamorphic prism pairs have certain advantages tho. Ease and stability of alignment (especially when things like the aluminum base-plates start heating up and expanding) is one aspect, and I believe they come in different magnification ratios. Or, have we definitely decided that cylindrical lenses are the best for small aperture sizes and far-field divergence? There may be other options too that have not been thought of or invented yet ..
-edit- There was one idea a few years ago involving a micro-lens placed very close to the diode emitter, I believe that it may have been a rod lens, to tame the fast axis quickly before the collimation and correction optics.

[kiyoukan]

Well from the ones i have seen used to correct beams the loss was higher than cylindrical lenses.
But im not sure if maybe someone got their hands on some 635nm coated prisms.
Also the nice things about these reds is they dont heat up as much as the blues or greens.
An well depending on if you use metal or plastic i think stability to the base plate is the same for prisms and cylindrical lenses.
I would be interested if anyone has high magnification prisms between 6x and 8x.

[Solarfire]

Prisms have bin outed a long time ago. BK7 is good for a maximum of 2.5x magnification, anything over that involves very high losses. SF11 can go up too 6x but the losses a unacceptable!

[kiyoukan]

So who else is sitting around playing with a 1W 635nm laser today?

Well then that puts it to cylindrical lenses as the winner.
Would anyone be up for a GB of those lenses i posted above?
6x setup. they do have a 7.7EFL lens so it could be a 7.792x setup but i think that the 6x gives us the best ability for beam sizes.

[steve-o]

I was playing with almost 1/2 watt yesterday
So what's the consensus on the best collimation lens to go with these new cyl lenses? Would a GB be possible with the col lens + the cyl lenses? (a lot to ask, I know ..)

[logsquared]

So who else is sitting around playing with a 1W 635nm laser today?

Not 1W today, but +2W

I think I'm sticking with the edmond lenses I've been using. I do wish the EO's came in 32mm length though. I might be interested in just your positive lens?

[kiyoukan]

Well daves lens seems to be the best.
I do have a place with a 2mm EFL lens with a diameter of 3.2mm but the lens will cost about 22$ in orders of 50.
Then on top of that i would have to get made a holder for the lens so the price would only be around 8$ cheaper than daves.
And would get the same result.
So unless my supplier lower the price i would say buy lenses from dave and correction optics threw the GB.

[steve-o]

Sounds good, thanx K.

[kiyoukan]

well actualy, i can get the aluminum lens holders for 3.58$ per for an order of 50 and in an order of 110 is 1.93$ a unit
So if you guys would want i could go and do that.
So the lens plus the holder would keep the price under 30$. But the lead time on the lens holders is 36days and the lenses would only take about 2 weeks.
Now that price of 30$ could change depending on the shipping cost of the order from china to here so maybe 1$ more.
So i can beat most prices but as a forum we would need to decide is this a good thing to do.
Dave sells alot of nice things, would it be worth it to save 10$? and under sell him?
He sells a good product and i would buy more often if he was state side.
That being said if any one wants to open a laser store state side im willing to work out a deal with you for suppliers just so we have a good source of parts here.