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Blu Ray Beam

ZRTMWA

ZRTMWA

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How many thousands of mW's would be needed to make a blu ray beam have the same visiblity as a 50mW or higher 532nm beam? I remember reading something about it on LPF but I can't find it. I do remember it was multiple watts. Also, what is the highest anyone on LPF has driven a 405nm diode to? I've seen a little over 500mW. Thanks.
 
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^I would doubt that once you take Rayleigh scattering into account that it would take thousands of mW.. Blu-ray lasers have the benefit of having a short wavelength. This means that the light gets reflected off of the molecules of the air itself, resulting in a more visible beam than should be possible at those wavelengths. The perception of this does vary slightly from person to person, but not by much.

How much power to equal a 50mW green? I would think that an 8X would easily equal (if not vastly surpass) the beam visibility of a 50mW green laser.
 
daguin has driven his @ 500 mw. I believe it is a 4:1 ratio. but i could be wrong. what type of lighting conditions are you talking about? daves 500mw should be as bright as a 50mw greenie. now if you are at a hooka bar, a rave, a dry ice making facility, these are all great condtions to see a beautiful thick beam of 405nm. now the more light in the room the worse because 405 is long wave uv, iirc, it disperses and makes it harder to see, similar to the effect of trying to burn your flesh with a red laser.


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blast to you elektrofreak, you beat me to it again.
 
Yeah I thought dave was the one who had the 500mW. So if I shined a 400mW blu ray into the sky at night and a 50 mW green, the blu ray would be brighter? I thought blu ray beams were much harder to see, more than a 4:1 ratio. By the way how much does a normal 8x cost because I saw the GB for only $93 and that sounds great. What would it take to equal a 200mW green, 800mW of blu ray?

Edit: I just saw that ff-racer drove his 8x to just over 500mW too. Hopefully it's not just because of freak diodes
 
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ZRTMWA said:
Yeah I thought dave was the one who had the 500mW. So if I shined a 400mW blu ray into the sky at night and a 50 mW green, the blu ray would be brighter? I thought blu ray beams were much harder to see, more than a 4:1 ratio. By the way how much does a normal 8x cost because I saw the GB for only $93 and that sounds great. What would it take to equal a 200mW green, 800mW of blu ray?

Edit: I just saw that ff-racer drove his 8x to just over 500mW too. Hopefully it's not just because of freak diodes
Click to expand...


You can't use just a pure visibility ratio with shortwave beams. Rayleigh scattering (reflection from air molecules) throws the perceived beam visibility off by quite a bit. Hell, I can see the beam from my 100mW PHR just fine outside at night, and I live in downtown St. Louis.


You'll have to combine several 8X's to equal the visibility of a 200mW green beam.
 
You can combine diodes? Or are you talking about using external optics?
 
You can easily combine two (only two) diodes using a 405nm coated PBS cube.. Such a system would be difficult to build inside a pointer, but the cubes for combining are readily available inside blu-ray drive sleds.
 
What's the percentage loss of mW's? Is there any? For example, if I combine two 400mW diodes into one beam, will the mw ouput be 800mW's?
 
The output would be near 800mW, but most likely not exactly. No matter what, any time you place any kind of optic in the beam path you lose power. There is no way around this. Coatings help reduce the power loss, but they do not eliminate it.
 
You can only combine 2 beams using a PBS, do some searching to find out why. A 500mW blue-ray has about 1/4-1/3 the beam visibilitly as a 80mW green. I have the parts ordered to create an 800mW blu-ray using a PBS for scanner I am building. I will have pics in a month or so.
 
ElektroFreak said:
^I would doubt that once you take Rayleigh scattering into account that it would take thousands of mW.. Blu-ray lasers have the benefit of having a short wavelength. This means that the light gets reflected off of the molecules of the air itself, resulting in a more visible beam than should be possible at those wavelengths. The perception of this does vary slightly from person to person, but not by much.

How much power to equal a 50mW green? I would think that an 8X would easily equal (if not vastly surpass) the beam visibility of a 50mW green laser.
Click to expand...

EF, I always wondered... there's "smoke in a can" to improve beam visibility on rooms. Now, what if that "smoke" contained fluorescent particles so tiny they wouldn't affect the transparent gas... you know where I'm going to :p? Could it be possible?
 
^It could easily be possible. The only issue I could see would be possible toxicity.. I believe it wouldn't be too hard to make a non-toxic fluorescent microparticles, but I'm no Chemist.
 
Some websites sell microscopically fine particles of non-toxic flourescent powder that can be mixed with paint. Technically, it is toxic if you breathe it in but you shouldn't be breathing in any particles into your lungs anyway. It could irritate eyes and nose if breathen in. It could even irritate the skin but is unlikely. Dust can be considered toxic if you breathe it in because it causes harm to your being, even if it is minimal.The particles are Alkaline Rare Earth Metal Silicate-Aluminate Oxide Europium Doped (Don't ask me what that is or how to make it). The particles glow for a very long time once charged by a light (or laser :)). But it ain't cheap. Here is one such site:

Glow in the Dark Powder

Radioluminescent paint is much better than luminous and flourescent paint IMHO because it glows without being charged. Only negative is its radioactivity. Tritium gas is radioluminescent when it comes in contact with a phosphor. This is how the tritium vials that Greg sells work. They are so tiny because the US Government limits the amount of every radioactive substance available, since they are constantly emitting radioactive particles. Because of their radioactivity it is very hard to find Radioluminescent paint. Some watch makers still use radioluminescent tritium paint for the inner face of watch dials. That's also how some gun sights appear to glow for years on end. I thought it was my imagination until I found out all this stuff yesterday while trying to find paint with tritium in it.
 
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Niko, didn't you say that some scorpions glows? You could always try grinding one up and throwing its particles into the air! :P

Or you could evaporate highlighter fluid to get the florescent properties of the solute in a solid form... I might try this.
 
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