Optima lens for reds

[The_Doctor]

Just to get ya back up to speed Doc, the lens of choice is the 2mm fl which Dave sells at his store, combined with a cylindrical lens pair which was a group-buy and I think Dr Lava sells cyls too. These work very well for the high power multimode P73 and G71 638nm red mitsu diodes, and some people are getting 1+ watt per diode from these with adequate TEC cooling . Not ion quality beams of course but the divergence has been tamed and imho the beams are of good quality.

I will never be in the fast lane. I move too slowly for that, and at times will drop out to do things like extend a phase modulation synthesiser I'm coding from scratch. Or playing bass guitar in a way that I hope might make JJ Burnel think "Ha, there's someone who gets it!"

Anyway, I looked at the 2mm FL thing a bit, but for now decided to go with 4mm and hope that this and the G71's will spare me some of the precision hassles of P73 correction and still get me a compromise I'm ok with. My first build will extend my original plans for a very small module so there's a limit to what I can get in there anyway. So a dual build will be first. I'll be cooling it internally, as one easy way to get some improvement in power and wavelength visibility. Dave sells a cylindrical lens pair, which I will probably use if I end up going for beam correction, but in my first builds I might equally decide if first tests look bad, to go for a longer FL and accept some losses just to keep it simple and small. Like I said to Andy, if I can rapidly come up with something good enough to pay for itself I can make better plans later. One part of my plan is to see what that driver of mine is capable of.

My wanderings on PL have often led in and out of the Big Red Thread *insert superscripted TM here* and maybe I'll think differently after reading things there I haven't seen yet, once I read it all. My main difficulty might be that I bought the non-adjustable mounts from Dave and can't do the FL<3mm adjustments, but my first base seems to be to make something sellable that is also fast and easy to work on if a buyer needs a diode refitting. If nothing else, an exercise in simple means is what I want first. I'll leave precision graphics-beam lasers to people who are better at it than I'll likely ever be,

[andy_con]

just go all out ;-)

http://www.laser-man.co.uk/projects/...ode-array.html

[The_Doctor]

Hell no! How they EVER got a patent for that I do NOT know... Anyway, it is cool, and I still have at least two pictures of that saved, and I look at them at times, too. In some way that thing reminds me of a big 8-valve amp deck I repaired for a Jamaican guy here once. KT88's. Now apparently doing hard time in the Star and Garter pub, the kind of work it was built for. Impressive stuff, but in an age where tiny solid state stuff sells better, that's the way I want to go. At least for now..

[planters]

Andy,

Two points about your example.

The 4 SM diodes need 4 collimation lenses,4 flexmounts and 4 prisms and I am assuming that this example is not using a PBS. The MM needs one collimator lens, two cylinder lenses and yes... two PCX lenses and 4 razor blades etc and produces a pretty clean beam.I bet the SM solution is more compact, but if you are looking for a multi-watt solution I know from direct experience that knife/knife edging 16 SM diodes can drive you a little crazy!

The other point is; do you have any images of what these multi-SM diode module beams look like far field?

[andyf97]

Just to get ya back up to speed Doc, the lens of choice is the 2mm fl which Dave sells at his store.

Would be nice to get some recognition each time this lens is mentioned .

On the other hand; do I want to be blamed for thousands of people not needed to buy red heads .

[The_Doctor]

The other point is; do you have any images of what these multi-SM diode module beams look like far field?

This is important I think. Given that multimode means at moderate fl like 4mm might make beams 4mm or more at aperture, but not a lot more a few tens of metres away, it seems that a beam can be built that appears not to diverge at all during the first few meters if the array at aperture is shaped similarly to the far field profile. Not that you can't do this with many SM diodes anyway, but the detail and precision is frightening to me, never mind thermal drifts on a base plate big enough. I haven't done it, but I have a very good imagination for tech detail at times..

Edit:
Now, is anyone going to tell me whether the crazy stunt of blue-coated 405-G-2's used for reds has merit? At least one person says it does, and his pictures impressed others. But I'd like to know a bit more about any attempts in that general direction. Efficiency, mainly... as in: does the good light gathering ability get ruined by losses in the wrong coating, or does it do so well in ways that make up for that?

[steve-o]

Would be nice to get some recognition each time this lens is mentioned .

On the other hand; do I want to be blamed for thousands of people not needed to buy red heads .

I thought about you Andy when I posted this, that's why I said "Dave sells at his store". I didn't say Dave was the discoverer of the this microlens ;] Although he does deserve credit as the finder of source/ supply of a lens that we needed. You discovered the concept, he researched a supplier. It was the time of the Grail. The peoples Republic of whatever are probably using our research and the resulting technology evolved at this site to build their product as we speak, and no one here is getting any credit .. it pisses me off too ..

[swamidog]

what's wrong with red heads? ;0

Would be nice to get some recognition each time this lens is mentioned .

On the other hand; do I want to be blamed for thousands of people not needed to buy red heads .

[andyf97]

I thought about you Andy when I posted this, that's why I said "Dave sells at his store". I didn't say Dave was the discoverer of the this microlens ;] Although he does deserve credit as the finder of source/ supply of a lens that we needed. You discovered the concept, he researched a supplier. It was the time of the Grail. The peoples Republic of whatever are probably using our research and the resulting technology evolved at this site to build their product as we speak, and no one here is getting any credit .. it pisses me off too ..

I am not pissed off at all; happy to help; even with manufacturers of the lenses but dave's bulk purchase will mean it in the end is best to get them from him, I am not on PL to make money from anyone. For me PL is a virtual space to help each other; less of an online market.

[andy_con]

sorry? you don't need any prisms for single mode diodes? yes you would need a cube but so what.

na combining lots of single mode diodes is easy and good fun ;-)
I really wana do another big diode build

Andy,

Two points about your example.

The 4 SM diodes need 4 collimation lenses,4 flexmounts and 4 prisms and I am assuming that this example is not using a PBS. The MM needs one collimator lens, two cylinder lenses and yes... two PCX lenses and 4 razor blades etc and produces a pretty clean beam.I bet the SM solution is more compact, but if you are looking for a multi-watt solution I know from direct experience that knife/knife edging 16 SM diodes can drive you a little crazy!

The other point is; do you have any images of what these multi-SM diode module beams look like far field?