My 1W 445 Module build using 4x Anamorphic prisms

[CDBEAM]

Dunno ??? I have not knife edged yet....just got talking with Dave at LSP on which bits to use...I would imagine it doed not matter...side by side....or upper/lower....very slight overlap....and...Sheeeezam !!! close to a box shape....I assume this is correct ???? comments from more experienced members ???? Thanx.

CDBEAM

[p1t8ull]

Jim, the reason the SA is corrected is that it's easier to tame the FA first with a commonly available focal length collimating lens to a spec that's easily good enough for our purposes, then use correction optics to sort out the SA.
Doing it the other way round and handling the SA with the collimator will require a much longer FL and bigger diameter lens (to capture the rapidly growing FA) and now you need bigger correcting optics to get the now huge diameter FA under control.

Using one set of prisms moves these diodes towards circular, adding another set to the other axis will improve things further (if you have it set up right) but I still don't think you will ever get a perfect beam, remember the emitter is far from square.
Just throwing it out there.. maybe we're trying to strive too hard for perfection? Maybe just picking the right collimator and applying some prism/cylinder lens correction to the SA will be plenty good enough? That along with a slight focus adjustment to give you a nice square spot at your chosen distance would be a very good beam, and a million times better than the 3-4mR 635nm reds we have all put up with for years with their heavy diameter, divergence, astigmatism/waist characteristics.
Out of a pair of knifed 445nm diodes I am getting about a 4mm beam with 1mR (26mm spot at 21m) with Aixiz collimators, and I think it looks bloody good. Yes the beam flattens a bit along the path (waist) but unless I walk along a static beam bobbing around like some kind of nutty duck I can't see it and really can't see it ruining an otherwise excellent graphics show.

I can see no real advantage in using 2 sets of prisms on the same axis TBH, unless for some reason you need a massive amount of magnification. Just use one set and rotate the first prism to increase the magnification and the second prism to turn the beam back on track. I have heard of some people seeing quite high losses, but are the prisms set up right? With Aixiz collimators I'm seeing about 3% losses through the prism set. With shorter FL collimators the wider angles mean losses will increase and maybe double to 6-7% or even more for very short FL collimators. The prism angles and relationship to one another are key to the performance with these things, click on the 'Specifications' tab of these prisms from Edmund, it'll give you an idea of the angles. Orientate them in the same way with the beam entering left and exit right for the most compact and efficient assembly -
http://www.edmundoptics.com/onlineca...productID=2429

[smogthemog]

Thanks for that Simon, thats cleared up a lot of wayward thoughts I was having about it all.
I am going in the shed in a while to try the extra 2 prisms in situe now the glue has set - the findings will be shared

[smogthemog]

Here are some photo's of the head just about finished, apart from a roof that is
Also, a few photo's of the beam at 10m.
I am getting 1150mW output after correction optics which i am more than happy with.

[edison]

Great nice beamshots!! Could you measure the beamsize after 10 meters just to compare notes?

Looking good smogthemog

[Laserman532]

you guys are doing some great work over there!

[smogthemog]

Thanks Pat.

Built up the Diode & TEC driver block this evening and accidentally fried my TEC while doing it
Thats what happens when you are listening to music and not paying attention to what you are doing

Pic's below:

[Zoof]

Here's a little template I made to align the prisms.
The magnifications are as follows, roughly:
50 deg : 1.8
53 deg : 2.0
56.775 (Brewster0 : 2.3

Hope this will help some people

printed at the right size, the black patches should measure 4x2 cm

[swamidog]

Rich,

it gets slightly warm (never hot) so I added a couple heat sinks.

Hey Swamidog,

What current you running your 445 at in this setup? Does the diode holder get hot at all or are you TE cooling it?

Cheers
Rich

[smogthemog]

A few more pictures of my Build and it then added into my projector. Sorry but no scanned shots as of yet as I have just coated my DT40 mirrors with first contact
The beam shots will come later

[beamann]

tracking thread for info on my RGB 5W build

[beamann]

please forgive me for my ignorence, but why all the prisims in 445nm beam line? Would'nt a collomater work to clean up the beam? or are they being used for another reason? I just to undestand and learn.

[michelrietveld]

working on first 1W blue with prism pair so printed out the template, will test this afternoon if i can improve the setup.

Michel

[borgqueenx]

gravediggers in action. ready set go!

So okay, i was given the zoof's PDF template, but since i also watch your guys photo's on this topic i have the feeling you all set the prism's on a different way.
So i need more instructions how to use Zoof's template. is the white arrow the beam thats coming? at exactly that arrow?
Then the laser needs to touch the prisms that way like in the template and then done?

[LaNeK779]

the answer would be "yes, yes and yes"

don't feel like a gravedigger, to me, this is one of the most usefull 445 posts ever made

[borgqueenx]

the answer would be "yes, yes and yes"

don't feel like a gravedigger, to me, this is one of the most usefull 445 posts ever made

thanks then i know what to do this saturday hope it wont be a disaster to place them.

[CDBEAM]

B-Queen...See attached Pic. This shows a single 445LD....mounted in a Brass Diode Mounting set for 5.6 diodes...from Laser Show parts. The best lens for collimation seems to be the O-Like Glass lens for 405/445 from O-Like. This lens is threaded and screws into the frt. end of the Brass Diode Mount. For beam correction...the Anamorphic prisms are placed in the beam path. The distance between Collimation lens to the first prism is typically kept rather short....15 ~ 35 mm. Position the prisms as shown....use the Zoof Templete....and you will acheive good beam profile....both for the Nearfield and Farfield. I should note that TEC cooling WILL be a good add-on for this diode. A TEC, finned heat exchanger and small fan will need to be added to the underside of the optical platform/base. WATCH your fingers while adjusting the collimation lens !!! " Oww...Shit....You Dummy " has been heard in Terrawatt Labs....MANY times!!!

Note: ZINGLE = one 445
ZUUL = two 445's
ZOD = four 445's

BEAM

[borgqueenx]

i have it running at low power first when im adjusting the G-1 lens. then when im done and the dot runs normal im going to put in the prisms, and after that im going to turn it back up to ~650mW.

thanks for the image, very useful

[borgqueenx]

oh but wait....now that im checking that image futher...The beam will actually be moved a bit? i already got my 445nm mounted. should i drill new holes or do you guys think it will still fit the dichro's?

[CDBEAM]

BQ.....Yes...the A-prisms do off set the beam propagation path....the drawing shows about 7mm off set. In reality...the off set is more like 4 ~ 5 mm. And Yes...start thinking about relocation of your 445 LD unit...you may need to......although....you will have some beam steering ability with the second prism....perhaps.....you could go that way !!! Your blue beam will then NOT be in a parallel to your Red and Green....So what....just adjust your Dichro to compensate...and you may be just fine. Good luck.

BEAM

oh but wait....now that im checking that image futher...The beam will actually be moved a bit? i already got my 445nm mounted. should i drill new holes or do you guys think it will still fit the dichro's?

[borgqueenx]

Okay right now im doing the installation of everything and the 445nm is real "wide" now, as a dot. Its like 3x35mm or something on about one and a half meter. Is that because ive done something wrong with the prisms, or is it the lens(g-1) or...?
Also its kinda bright in standby and turning the bias down wont resolve it.
And finally its blinking sometimes in a steady way. like bleep....bleep....bleep...(about 3-7 times i didnt count) not with different seconds between the blips)
I have a flexmod p3 as driver.
Thats what i need resolved, hopefully you guys can help me

Edit: just tried it on the galvos and seems there is no blanking...how can i fix this?
Edit2: maybe its the standby current thats making me think there's no blanking...i have the feeling its that.
edit3: here's a video showing it:
http://www.youtube.com/watch?v=quSEE6p0-5c

Edit: continuening my problems in the help forum, please reply there..