Paradigm Shift, My A$$!

The second law of thermodynamics has a optical corollary, Etendue.

Etendue says, you cant win, you cant loose, you cant even play the game.

Translation, no output beam passing through passive optics can be brighter then its source, more so if you try to shrink the diameter while trying to make the beam parallel.
Think irradiance,not burning things.

Fine folks, all of you who are going to sell me your 473s so damn fast and so cheap, just go ahead. You really need to think about that before you do.

Oh, and enjoy the ride, because having got a glimpse of what Nichia is going to offer next, these small chips are not going to be here long, and the next thing for laser video has a beam you could not get into 600 micron fiber...

Yes, I bought two, but I have access to a combining technique that is too expensive for the average hobbyist. I'm going to throw away 1/3 to 1/2 of the power to even get close to a decent beam.

Slow down folks, these Nichia things are not quite what many of you think they are...

Just a public service announcement from the craggy ole Ghost of Laser Xmas Past....

Who once upon a time, some years ago, bought a first generation high power red, costing two weeks pay.... The spex are not all that different...

Prove me wrong..
Steve

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Originally Posted by mixedgas

The second law of thermodynamics has a optical corollary, Etendue.

Etendue says, you cant win, you cant loose, you cant even play the game.

Translation, no output beam passing through passive optics can be brighter then its source, more so if you try to shrink the diameter while trying to make the beam parallel.
Think irradiance,not burning things.

Fine folks, all of you who are going to sell me your 473s so damn fast and so cheap, just go ahead. You really need to think about that before you do.

Oh, and enjoy the ride, because having got a glimpse of what Nichia is going to offer next, these small chips are not going to be here long, and the next thing for laser video has a beam you could not get into 600 micron fiber...

Yes, I bought two, but I have access to a combining technique that is too expensive for the average hobbyist. I'm going to throw away 1/3 to 1/2 of the power to even get close to a decent beam.

Slow down folks, these Nichia things are not quite what many of you think they are...

Just a public service announcement from the craggy ole Ghost of Laser Xmas Past....

Who once upon a time, some years ago, bought a first generation high power red, costing two weeks pay.... The spex are not all that different...

Prove me wrong..
Steve

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Cant slow down now steve, it is a feeding frenzy, its insanity!!! its BLUE!!!! (yeah im not impressed either) but it beats garden hoses :)

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Originally Posted by mixedgas

Oh, and enjoy the ride, because having got a glimpse of what Nichia is going to offer next, these small chips are not going to be here long, and the next thing for laser video has a beam you could not get into 600 micron fiber...

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Screw DLPs- and I say that as an ex-TIer- because MEMS galvos are the next big thing, and yes, they do need small beams to match their small mirrors.

Who needs fibre-fed heads when you have multi-watt diodes?

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Originally Posted by heroic

Screw DLPs- and I say that as an ex-TIer- because MEMS galvos are the next big thing, and yes, they do need small beams to match their small mirrors.

Who needs fibre-fed heads when you have multi-watt diodes?

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DLP has the advantage of achieving cinema theater power levels which could be a potential problem with MEMS. The eventual goal is to eliminate shipping film worldwide, as far as that goes...eliminate film all together...and it will happen...it is just who has the best format for large projection ..As far as personal presentation projectors i suspect LCOS will be the inexpensive alternative....IMHO

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Originally Posted by Laserman532

DLP has the advantage of achieving cinema theater power levels which could be a potential problem with MEMS.

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I'm not sure you're right... commercial power semiconductors tolerate power densities of gigawatts per cubic centimetre. Suffice to say that people smarter than me are working on these systems and when I've spoken to them they were optimistic about the ability to reach very high power levels. One point to remember is that these MEMS based systems eliminate the need for a lot of expensive optics (it's hard to keep your pixel array straight and flat over a wide zoom range, as is needed for portable business projectors) by simple dint of being laser projectors, so they may end up being cheaper than the alternative, just as long as the light sources come down in price.

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Originally Posted by heroic

I'm not sure you're right... commercial power semiconductors tolerate power densities of gigawatts per cubic centimetre. Suffice to say that people smarter than me are working on these systems and when I've spoken to them they were optimistic about the ability to reach very high power levels. One point to remember is that these MEMS based systems eliminate the need for a lot of expensive optics (it's hard to keep your pixel array straight and flat over a wide zoom range, as is needed for portable business projectors) by simple dint of being laser projectors, so they may end up being cheaper than the alternative, just as long as the light sources come down in price.

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i stand corrected...I just have a spot in my heart for DLP, and I figured that projection lens technology cant be improved on...much......it is an amazing piece of art (probably captured alien technology...kidding of course). The DLP "projection" was just an side application of the tech.

The big money maker for the DLP is basically a single use device :) sorry to say

Guess the bottom line is....even with poor ratings from who knows who....it's a chance for the blue laser to become reality to a lot of people.... the ones that are laser minded. I for one jumped with joy at the chance at cheap blue....I have talked of this over 4 years ago on PL. Now it's here. In my hands. Even if the beam is a little large...so what if you have 1 watt of it. That would cost $$$$$ or more for 473nm...not to mention 457nm I was almost ready to buy into. So now I get to really play with this sometime....soon I hope. Having not seen it myself , 445nm alone, I am certain it may pose an issue to be dumbfounded with for quite some time. I had plans to build a dual right off the bat....maybe next projector. We need to look at this with a limited time frame I feel, as Mixedgas pointed out, as bigger and better may push these away from top manu priority. Even if the next generation has a huge 635 ish beam....they can be tamed enough to hit the mirrors. But at a cost in power and optics expense. I say enjoy. One issue that I and Mo spoke of.....no one has created a viable solution for a decent 1 watt single diode red. Maybe another time for this. Hint.......wants a 642nm diode...say around 100um chip......around 1/2 watt...near $200 each.

I think what IS happening here is that people like myself, who have looked at their hobby projectors and seen they're going to need >300mW of 473nm, have basically had to say no (I'd be looking at around £1500-£2000 to do my pair of projectors) and stuck with big greens or RGY's.
Now there is a chance to get some blue that isn't 405 (i.e. nearly a proper blue) for next to nothing, and being a diode, can get into a small form factor (I didn't even think I'd fit a blue in my cases!) I reckon I'm in for about £300 for the pair which is really pocket money prices - what's to lose?

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Originally Posted by Laserman532

The big money maker for the DLP is basically a single use device :) sorry to say

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I met the guy who invented DLP while I was at TI. He told me what they're used for; I looked into it, and then quit a month later... part of it was that I had a better offer, and part was that I don't like working for that kind of customer.

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Originally Posted by heroic

I met the guy who invented DLP while I was at TI. He told me what they're used for; I looked into it, and then quit a month later... part of it was that I had a better offer, and part was that I don't like working for that kind of customer.

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spreading democracy through technology :(

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Originally Posted by mixedgas

The second law of thermodynamics has a optical corollary, Etendue.

Etendue says, you cant win, you cant loose, you cant even play the game.

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Hey Steve,

sure you're right about this, but only if you're not willing to trade power. It is always possible to cut out a fraction from your transversal phase space with the corresponding loss in power. One Example: In my work I did spectroscopy and needed a spatially coherent beam of light from 600nm to 1000nm wavelength. I ended up coupling an arc lamp into a single mode fiber. Perfect beam quality but I lost 99.999999 percent of the light. :D
I haven't done the math here yet but assuming the emitter size is double of the 500mW Nichias which are known to collimate quite well, I would say with loosing 50% of the power one can get a good beam (define good :p).
And I think thats the point here: Now this diodes are so cheap that it simply does not hurt to throw away half of the light and 300mW of blue is still a lot for the average hobbyist projector.
Anyway this will be just a transition phase, I think. All this modern mobile projectors like the piccoprojector use single mode blues and it is just a matter of time till these are cheaply available as well. I think all the enthusiasm comes from the fact that now for the first time a really high power blue laser was used in a consumer product. I await more to come!

Greetings
Andreas

while I agree I also disagree... it might not be a paradigm shift for the entire laser show industry, but it sure will be for chinese projectors... which means more watts in the hands of people that shouldn't be entrusted with a 5mW pointer

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Originally Posted by heroic

I met the guy who invented DLP while I was at TI. He told me what they're used for; I looked into it, and then quit a month later... part of it was that I had a better offer, and part was that I don't like working for that kind of customer.

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Intriguing . [popcorn]

Indeed.

Totally wild guess, take a DLP chip, add a lens as if you were building a video projector (but made to pass far IR), now replace the lamp with a thermopile (or other non imaging IR sensor), apply suitable video signals while monitoring the thermopile output and you have effectively built a flying spot scanner in the deep IR (The spot size is variable so you can do a fast course scan then narrow down once you have some targets). In practise you would play clever binary search games to optimise acquisition time.

You would want to cool the mirror array and the sensor for best sensitivity, peltier effect in a toy, or expand a small tank of liquefied gas across the sensor in a real one (and an N2 fill would be good to prevent condensation).

An IR Missile guidance camera that John Logie Baird would have recognised!

Just a wild guess, but it seems like something that would work.

In fact a fun lab experiment given that we have all these dead single chip video projectors kicking around these days might be to place a photodiode in place of the light source and make a flying spot video camera....

Regards, Dan.

Actually, with the addition of a moderate rep rate q-switched laser (dpss yag would work reasonably well) it would be very possible to make a time of flight camera out of it. If it runs at 85Hz you would get an effective 250Hz update rate by (since you don't care about r/g/b), if you want say a .1Hz update rate (not stellar, but I would say its usable) you can get 2500 pixles- a 50x50 grid. I then propose that with some careful optics you could use several detectors (perhaps divide the chip into quadrants? a 3x3 grid should also be possible) and you are getting into 100x100 pixel range, which is better than most of the demo units I have seen.

I propose the down conversion circuitry shouldn't be that hard to make, 1" works out to about 100 picoseconds in the time domain, so with a 10GHz clock source (downright easy with mini-circuits type stuff) and a good quality PIN diode you should be able to get going for less than the blue you just didn't buy would cost.

So, your saying take the vag burner and an old projector out sailing and make some pictures of the wrecks on the bottom of Liverpool bay?
532 will penetrate sea water quite well, and the time of flight will take most of the turbidity out of the picture.

Actually if the illumination and the camera are pointing the same way, you only need 5Ghz as it is round trip time you are gating, but that charge amp will need to be fast..

Interesting notion, and you might be able to do quite a bit better then that resolution by playing tomographic games with the fact that you can switch multiple points on the mirror array to the sensor for each shot (Then do a sort of computed tomography type thing to produce the final image).

This needs thought (And I need to pick up one of those projectors).

Regards, Dan.

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Originally Posted by DMills

Indeed.

Totally wild guess, take a DLP chip, add a lens as if you were building a video projector (but made to pass far IR), now replace the lamp with a thermopile (or other non imaging IR sensor), apply suitable video signals while monitoring the thermopile output and you have effectively built a flying spot scanner in the deep IR (The spot size is variable so you can do a fast course scan then narrow down once you have some targets). In practise you would play clever binary search games to optimise acquisition time.

You would want to cool the mirror array and the sensor for best sensitivity, peltier effect in a toy, or expand a small tank of liquefied gas across the sensor in a real one (and an N2 fill would be good to prevent condensation).

An IR Missile guidance camera that John Logie Baird would have recognised!

Just a wild guess, but it seems like something that would work.

In fact a fun lab experiment given that we have all these dead single chip video projectors kicking around these days might be to place a photodiode in place of the light source and make a flying spot video camera....

Regards, Dan.

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spreading democracy and building jobs for americans one boom at a time.