Laser VS ULTRA-ULTRA BRIGHT LED

[kiyoukan]

Been looking for a very bright blue laser. i decided on a 405nm blue / violet laser from high tech deals the SF-AW210. A friend of mine who works on LEDS told me i could get a 1 WATT BLUE ULTRA-ULTRA BRIGHT LED and with the proper lensing get a better visible beam. due to the fact its blue not violet. here are the specs of the LED 19/ 31 Lumens @ 350/ 700 mA
100 degree viewing angle
Maximum forward voltage: 4 Vdc
Maximum forward current: 350/ 700 mA
I personaly think hes crazy but i would rather check before i buy.
I just plan on putting this threw 1 stationary diffraction grading then 1 turning at 5rpm.

 

[Jaseth]

Light from an LED is not coherent - ie, it goes all over the place. You will only be able to focus it a very small distance and the beam will be fat and quickly get huge.
31 lumens is also not a lot.

Seb

 

[styropyro]

A 1 Watt LED does not output 1 watt of light, that is just the wattage going into the LED. a 1W laser diode outputs 1 watt of light at a set input wattage.

BTW you can't focus an LED into a beam like you can with a laser diode.

 

[kiyoukan]

Glad i got this cleared up. finally going to the check out counter. how many lumens is a laser or is there no comparable measurement?

 

[nikokapo]

Glad i got this cleared up. finally going to the check out counter. how many lumens is a laser or is there no comparable measurement?

Lasers are commonly measured in units of power (W = Watts). You'll usually see them in the order of m (mili); i.e. mW (miliWatt).

 

[Cyparagon]

31 lumens is also not a lot.

Seb

It IS a lot if it's all in one place. It takes 440mW of 473nm light to give 31 lumens, and it takes 72W (yes, seventy two watts) of 405nm light to give 31 lumens.

Even Gus's 8W argon only gives out ~1000 lumens... about as bright as a 75W bulb.

 

[kiyoukan]

Hmm so the light can be focused with a lens but if you use 2 lens cant you stop it from getting bigger? or will it just take longer.
i am making a kind of star light as a gift for Christmas. It only needs to go threw 2 diffraction lenses enough to make what appears to be stars. This thing could be left on for hours possibly up to 12. That is why the led seemed so attractive. But if i use 2 lens could i focus it for this? Also the laser that i am buying if i turn down the power and with a heat sink what is the max run time you think i can get with out risking any thing. I am just looking for blue dots circling on the ceiling. I have given up for a visible beam as that seems way out of price for this project.

 

[Helioplasma]

Using two lens is useless. Having two lens will reduce the amount of light because a lens doesn't let through 100% of the light.

You could use a BR and paint the wall with fluorescent dye if you want a blue star-field projected to the cieling. With proper heatsinking if you need 12 hours of continuous use.

 

[kiyoukan]

You could use a BR and paint the wall with fluorescent dye if you want a blue star-field projected to the ceiling. With proper heat-sinking if you need 12 hours of continuous use.

?BR?

Could a SF-AW210 BluRay 405nm 200mA Laser if turned down the power to about 100ma-150ma and a good size heat sink such as DJR Full Body V2 Heatsink, this thing could run with out worry of burning out?
Is the SF-AW210 over kill? for what i want would i be better off going with a 405nm PHR-803T and running it at 60ma?

 

[Helioplasma]

BR = Blu-Ray.
You could use a SF-AW210 at low currents so it can last longer, but I recommend using a relativaly low powered laser diode for safety reasons. (like 15mW-20mW before diffraction gratings)
On low powers you can use a heatsink like this, no problem, although the bigger the better.

 

[Jaseth]

It IS a lot if it's all in one place. It takes 440mW of 473nm light to give 31 lumens, and it takes 72W (yes, seventy two watts) of 405nm light to give 31 lumens.

Even Gus's 8W argon only gives out ~1000 lumens... about as bright as a 75W bulb.

This is very true, however we are talking about non-coherent light here. It's already very difficult to focus even at short distances and he is talking about putting it through diffraction gratings.. after that the light is going to be nothing but a very dim flood light on the wall.
If we were talking about 31 lumens of coherent 473nm light, this would sure be one laser I would like to get my hands on :evil:

I have tried focusing about 630 lumens of light with optics ranging from tiny lenses to an 8'' magnifying glass and the beam sucked at all times.

Seb