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

[steve-o]

Looks like about 5x6mm at the aperture. I haven't measured the divergence yet. The aixiz lenses aren't probably what I'm going with, just had them on hand.. eagerly awaiting Dave's 2mm in the GB ..




The bottom pic is with no fog/smoke added to the air, just good ole clean appalacian mountain air. It's putting out some power, I'm sure a lot of losses though with the aiziz clipping the beam and the dust that seems to be magnetically attracted to the optics.. maybe the mountain air isn't so clean.. ? No pollution tho .. maybe dinosour dust ? :]

[steve-o]

And now, for some more gratuitious beam shotz, this time with some smoke in the air..

[badger1666]

Nice pics Steve
What's the apeture beam like with first lens further away from aixiz?
Does it get bigger

[LaserCo]

Well…I have been working on a new design Laser Diode mount with an adjustable lens arrangement. This design will work very well with Dave's 2mm fL Collimation lenses… as the very small focal length demands precise X-Y placement of the lens relative to the G71 diode axis. I placed this info here…because this thread has become the general catch-all for anything related to the G71…especially optics.

Please see the attached pics and drawing. B4 you question the over the top nature of this design….yes…I agree it MAY be a bit OTT…but humor me….I want to do the best possible job at taming this diode…I think we have FINALLY arrived at the optimal optical lens selection….I want to achieve optimal alignment with minimal aberrations…with the LEAST time/work. If you share the same perspective…..you will see the value in this design…which basically keeps the LD position constant…but provides adjustability for the collimation lens.

To start…there is a cylinder within a Brass Main block. The main block was machined from 1 ½” square (38.1mm) Brass bar stock. The cylinder is a modified Axiz Copper Module with the G71 pressed in. I prefer the pressed in design because….the first contact with the LD is a very tight fit…providing the best thermal transfer between the diode and its host. The cylinder was chosen because we need to have the ability to rotate the LD/Copper host to correctly orientate the LD slow axis for the optics correction. Of course…the interface between the Axiz module cylinder and the Brass Main block will have an extremely thin application of OCZ Freeze Thermal paste. After the slow axis position has been set…the cylinder module is then clamped with 6-32 set screws ( S1 and S2 )

Next…the main feature of this design…the ability to adjust the X-Y position of the collimation lens. The pics show a 405-G2 lens. I have the LSP 2mm collimation units on order. The lens is screwed into a brass disc with a M9 threaded bore. This position disc sits in a recessed pocket with a 25.4mm ID bore. The disc is held within the pocket by an acrylic capture plate. This plate is secured to the main block with four (4) 4-40 bolts (C,D E & F). The thickness of the position disc and the recess pocket must be equal to allow the disc to move in the X/Y…but not the Z direction. Two (2) very small springs are placed in the gap between the disc OD and recess pocket ID. These springs ( 3/16” dia.) apply pressure toward the positioning Bolt A and Bolt B. So…by adjusting the A and B bolt….the position of the disc….and the collimation lens axis…can be aligned to the LD axis.
So…there you have it…Another techno wonder…from Terrawatt Labs. This unit does take some time to machine. I may sell these. PM me if you are interested. Thanx for reading all this blah, blah !


BEAM


Note: Some pics are of the finished build and some pics are as the build progresses.

I have had these for a while now and was real surprised!
Look at how similar these pneumatic? cylinders I have are to
what you have created! I have these square ends to them and discs that you
can see if you take a look.
No machining required. Go Green, save the earth of co2 contamination.

I had to take a screenshot of your "Attached Thumbnails" and put it
in my image folder of the pictures I took of these things, your thumbnails
would not show up when I hit Preview Post, this was kind of a PITA.

CDBEAM I have really enjoyed your style here on the board






I have been informed that my images are not showing, so (crossing fingers) try this
instead. (Sorry)
https://www.dropbox.com/gallery/5346...Mount?h=39a198

[CDBEAM]

Well...how about that !!! What is the center bore dia. ??? Might be a inexpensive replacement ! Cylinder material ? Approx cost ? BUT....I must note....that my design runs ONLY on hot air !! hahahaha The basic question is...Is such an OTT design necessary ?? Well...perhaps not necessary....but a welcome component to deliver maximum alignment of the 2mm Collimation lens to the G71...with minimum time spent " fiddlin around "...like I said...acheiving optimal alignment with the 2.9mm lens was a major pain.....In theory....the 2.0 will be even more sensative...Thanx for the comments....BEAM

[steve-o]

Nice pics Steve
What's the apeture beam like with first lens further away from aixiz?
Does it get bigger

Thx Badger,
Well, I moved the lenses out to the 70mm length and I was surprised to see no changes at all in the near-field or far-field beam dimensions. At least nothing that I could see visually or measure. I was searching for any minute changes at all, and I thought for a moment that maybe the far-field was a bit smaller, but no not really. Nothing. Nothing at all. Strange .. ?

[steve-o]

I'm beginning to wonder a few things about over-driving these diodes.. At twice the rated max current, they don't instantly pop a cavity mirror (result=cod) , that means they can take it. Heat generation; they seem to stay fairly cool at said current. (junction temp unknown) I understand about derating semiconductor components, but when boiled down to just a few critical operational components, where is the failure going to come from .. ? Root cause analysis/ (calling Mr. Professor SR.. )

[LaserCo]

The ID measures to be 27mm, they are made of aluminum. I have only one of the pistons that fit within it and there are no more, it fits loosley because it is surrounded by O-rings I suppose.
The walls 5.5mm at the thick part and then the the thin/inside part between the "fins" measure 2.7mm (pretty darned thin! )

The discs are 8.9mm at the thickest point and are a real tight fit once inside the cylinder's end, they do not go flush though, they stick out probably 1/2mm, the ones in the photos have holes in them because I drilled them and they have slots around the circumference.

I have the tap and die tools to thread these for Aixiz lens barrels.

I have bronze bearings or bushings (not sure what they are called, I bought them at the hardware store) that fit into them like the aluminum discs do but they DO sit perfectly flush when turned around.
I bought them for dirt cheap but of course they are of high value to me.

Your cubes have a thicker wall than these things do obviously.


I have heard you can go to the craft section at a store like walmart and find aluminum oxide powder, I have been trying to remember what to look for exactly. I have thought of mixing it with epoxy and stuffing one of these.

I also have a 5 oz tube of Bondo Plastic Metal 901ES, its ingredients list Aluminum and Magnesium Carbonate. I have not opened the package yet because I have not decided the stuff would work and am seeking opinions, here is its webpage that show its ingredients:

I have an earlier photo I took, you can see the bronze bushing sticking out of one.
http://multimedia.3m.com/mws/mediawe...9lxtD7SSSSSS-- What a weird address, it is a PDF file!

[LaNeK779]

Have you tried to contact Flaminpyro on the other forum:
http://laserpointerforums.com/members/flaminpyro/

The only way i scored a pair of Dr. lava optics was second hand however Flaminpyro is a distributer of Dr. lava's drivers so he might be able to get you a set or he might even have some available. Its worth a shot.

Hope that helps some.

well, i am not going to register just for this. is this guy posting over here?

anyway, thanks for the heads up lazeerer!!!

[steve-o]

What's the apeture beam like with first lens further away from aixiz?
Does it get bigger

Well, I tried it with a different lens this time.
Experiment #2. Removed Aixiz collimation lens, installed Thorlabs 350340-A lens. A significantly smaller aperture beam size (3x4mm) was obtained along with increased power output.
Experiment #3. The cyl-lenses were moved close to the emitter of the LD (~2mm), result: the far-field (100 ft) 'spot' size was larger than the dpss reference spot. (see image # 1) When the cyl-lenses were moved to 70mm from the LD, the spot size was improved (smaller ) see image #2. Sorry for the extreme blurryness of the pics but I had to use a lot of zoom to get 100ft photos and I couldn't hold the camera still enough (prolly too much coffee lol) but still can see a small improvement in far-field spot size despite fuzzy photos. There was no noticeable change in the near-field 3mm x 4mm (aperture) spot-size. Hope this info is helpful.