now all the laser manufactuers have had a smack in the face with the arrival of cheap blue 445nm
does this mean the prices of 642nm and 532nm are going to go to compensate ?
bloody hope not
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now all the laser manufactuers have had a smack in the face with the arrival of cheap blue 445nm
does this mean the prices of 642nm and 532nm are going to go to compensate ?
bloody hope not
We need to talk Casio into using 642nm diodes for red. *retardoQuote:
Originally Posted by badger1666
i sure somwhere there's a manu working on somthing to rival casio and lets hope they are doing just that, using 642nm
well i hope so
So what are the beam specs of your cheap blue.Quote:
Originally Posted by badger1666
there is a big chance the cheap blue isn't that cheap anymore after you are finished shaping the beam.
Maybe the cheap 635nm red will be an option to match the bad divergence of the cheap blue.
The blue is cheap.... throw away 50% and use a beam shaper to get what you need. Cheaper to add another diode than to buy fancy optics.
You can't alter divergence by just 'throwing a piece of the beam away' ...
yeah but surely if the far field beam for example was 4mm x 20 mm and you cut it in half its now 4mm x 10mm granted the divergence dont change but the beam size does :confused:
@ mc carrot i could spend £400 on optics to fix the beam so it usable £30 on a diode and only end up 250mw from that 500mw diode its still cheap compared to anything else out there
Quote:
Originally Posted by FourDee
Please correct me if I'm wrong, but I think what is being proposed is the following... By collimating a beam to acheive a desirable divergence you may as a direct result increase the diameter of the beam. By masking with an iris, aperture or reflecting only a portion of the beam off your scanners, you would maintain this desirable divergence. You would just "throw a piece of the beam away".Quote:
Originally Posted by FourDee
A note-
With a large emitter such as this laser, it is entirely possible to pass the beam through an aperture to 'clean up' the beam. This is NOT possible with a singlemode diodes, since the beam is already as good as it gets--you can pass the beam though a pinhole to make it more round/less noisy, but the improvement on the divergence is minimal.
The extreme case of loosing light from the 445nm diode would be sending it through a pinhole that is sized to be diffraction limited (roughly (wavelength*focal length)/(pi*radius incoming beam)-which would only let the light that fits a gaussian profile due to some linear combination of wavefronts blah blah)--and give you a more or less diffraction limited beam. Of course in that case you won't get much power through, but you can go for a slightly less extreme case where you cut off perhaps 1/2 of the beam, which should give you a decent improvement in beam profile.
But blocking 1/2 the beam is blocking 250mW, this is tranfered into heat. your collimator wil get hot very fast!
...assuming the clipping is done within the collimator, and not after using a heat-sunk aperture/iris thing.Quote:
Originally Posted by mccarrot
well my plan was this, find a lens that gave least divergence and 6mm beam cut the beam in halfwith a mirror, then fold the rest of the beam back around on its self and knife edge the two back together again should end up with a 3mm x 4mm beam @1.2 mrad
it might suffer a bit of loss on one of the beams but for cost it proberly my best option
and it leave it open to do the same with a second diode and pbs cube together the two diodes
You seem to be forgetting that these diodes have two very different axis.
The way you want to do things will result in the following:
- Near field: - (rectangular with the horizontal side widest, or if you clip the whole thing, square/round)
- Far field: | (with or without clipping)
HEY! You guys are drifting a bit... Keep those comments in the lense thread. *retardo This thread if for "How are we going to get those 642 prices down?". *vigil
Well how about some suggestions on the most economical reds and greens to accompany these blues? Other than the Opnexts, can anyone suggest some 640 single/multi mode diodes with adequate performance that would require only a couple of to combine with the Casio blue?Quote:
Originally Posted by allthatwhichis
Mitsubishi 638nm's look interesting, but not sure what the beam profile would be like. I read somewhere they are available up to 500mw now, though not cheap
http://japantechniche.com/2010/01/15...ishi-electric/
http://global.mitsubishielectric.com...10/mel0772.pdf
thats not quite what i mean look again;)Quote:
Originally Posted by allthatwhichis
it was can we expect to see a price rise in the red and green's
because manufactures blue sales have taken a knock.
but i will settle for your suggestion:D
group buy after all this blue stuff settles down