5mm LEDs - how blue does it get?

[Skywise]

Ok, so I have been on a bit of an LED kick recently, so figured I might find like minded addicts here. I'm a bit done with the high powered LEDs after playing around with some Crees and am currently mostly fascinated with the clean color LEDs produce.

I've obtained a 100 455nm blue LEDs but am wondering if there's any lower nm blue LEDs available, preferable in the 5mm packaging (tho I am also a bit curious about the cheap 5 die 100mA LEDs I've been seeing online). Any opinions?

My current "project" is a deep blue lit opaque acrylic cube for my desk (cubicle rat at a dot.com), so I am also wondering how I can diffuse 5mm LEDs most effectively.



-Sky

 

[paulr]

Yes, shorter nm than blue is so-called "royal blue", then violet, then several wavelengths of UV. I don't know what exact nm goes to which designation but all of these are available, down to some 250(?) nm or so UV leds reviewed on www.ledmuseum.org . Those last are pretty exotic though, most garden variety UV leds are something like 390nm.

 

[TONY M]

Paulr, can you get good pure white 5mm LED's?

 

[paulr]

The ETG 5mm white leds used in the Arc and Peak "Snow" flashlights are pretty neutrally colored if that's what you're asking.

 

[TONY M]

The ETG 5mm white leds used in the Arc and Peak "Snow" flashlights are pretty neutrally colored if that's what you're asking.

Yes thats what I wanted to know, thanks!

 

[Skywise]

Thanks for the info. I've seen the old 430nm blue LEDsm but their spectrum is quite wide overall. Any idea if anything with a very narrow 430nm spectrum is available?

-Sky

Err.. Nevermind on the 430nm availability, Google answered that

 

[Ken_McE]

I am also wondering how I can diffuse 5mm LEDs most effectively

You might try lightly sanding the end of the LED.

 

[Skywise]

I've never thought about that. Tried it with some old white 5mm LEDs I had floating around and it works quite well. Might get a small container of quartz sand, I bet shaking the LEDs in the sand beats even the sandpaper.

Honestly feeling a bit stupid now, I've always been hunting for 120 degrees and more LEDs for my project, when there's such an easy alternative.

-Sky

 

[paulr]

I bet sanding loses some light. Surefire incans use holographic diffusers which lose a lot less light than translucent filters. If you want to buy 100 leds at a time, http://store.nichia.com is the obvious place and there are wideangle ones available.

 

[Skywise]

Just wish they has GS-K1s available in 100 packs for the US...

 

[The_LED_Museum]

Kingbright # L7113NBC 450nm blue LEDs might be the shortest wavelength blue LEDs that are easily available; though as I understand there is a minimum purchase of 500 pieces from (I believe) Digi-Key.

This is a spectrographic analysis of one of these LEDs, showing that it has a relatively narrow spectral line halfwidth.

 

[Skywise]

Thanks for the info. I found a supplier that claims a similar narrow spectrum around 450-455nm, will see how those work out.

 

[almscot]

Hey Skywise,

What did you find for those 450nm-455nm LEDS?

Let us know.