Blue-ray laser diode + phosphor = hi-power white LED?

[PhotonWrangler]

Now that blue-ray laser diodes are out, I'm wondering whether one of these LDs could be combined with a phosphor dome to make a super-bright white LED? (LELD? Light emitting Laser Diode)

Does the phosphor have a saturation point where any input increase beyond a certain power level results in no further increase in brightness? Can someone with a blue-ray diode try shining it at the phosphor coating of a white LED to see what happens?

 

[The_LED_Museum]

I've tried irradiating white LEDs with my Blu-ray laser, and the phosphor formulation used in modern white LEDs is definitely *NOT* tuned to the sub-410nm wavelengths as output by Blu-ray laser diodes. The results range from fairly faint to a moderately dim yellow glow. :shakehead:

 

[nerdgineer]

The total power output of a laser diode is much less than that of the blue LED substrate underneath a white LED (200 mw vs. 3000+ mw). You wouldn't get any more - and in fact less - power.

The power density of the laser diode at the point of emission is no doubt higher than LED substrate but a yellow phosphor over the blue laser diode would (as you note) a) saturate, b) decorrelate the coherent blue light and c) absorb a lot of the blue light.

 

[PhotonWrangler]

Thanks guys. Craig, I know that most of the phosphor formulations are tuned for a longer wavelength of blue; however I have noticed though that some of the slightly warmer-white formulations (such as the one that came in my photon freedom) seem to be a little more responsive to NUV wavelengths. And I know that there are some UV-excited white LEDs out there, so there's got to be a phosphor available.

NerdEngineer, thanks for your input also. I had a suspicion that the phosphor has a limit to it's transfer curve. And it's a good point that an LED die produces a lot of light in a lot of different directions. I guess it's more efficitent to capture a lot of that light distributed over a wide area of phosphor coating rather than pound a small phosphor dot with a blue laser.