Why does nobody bin 420nm any longer?

[photonwave]

I've been working my eyes and ears off trying to find a company that produces 1W or higher 420nm violet LEDs. My closest source, Kingbright, discontinued them. All the Chinese manufacturers that I used to do regular business with no longer stock 420nm diodes. Hunting Cree's website, I can't find them any longer (they used to have the megabright 410nm diodes,)

It's frustrating. It appears as if nobody has any use for 420nm LEDs and thus people are no longer stocking them. I most certainly do have a use for them, I want to get mankind out into space and those are key!

Is my Google-fu that weak or is 420nm going the way of the dodo?

 

[evilc66]

http://www.roithner-laser.at/All_Datasheets/Pricelists/roithner-pricelist-c-100111.pdf

Search for H2A1-H420. There are other 420nm LEDs in there also. Not cheap.

 

[Gomer]

The natural progression to this conversation (since this looks like the common reef related question), is what is the source for the "now appearing" 403-405nm LEDs in reef lights? (beyond the 5mm ones)

 

[photonwave]

The natural progression to this conversation (since this looks like the common reef related question), is what is the source for the "now appearing" 403-405nm LEDs in reef lights? (beyond the 5mm ones)

Too deep for my usage, unfortunately. Must have 420nm and cannot go lower.

Well, I could use some 290nm as well. Some plants, like tomatoes, love some UV for essential oil production.

Not for reefs but close! More for targeted customized panels for horticultural applications on ground, and eventually in space (I hope.) I've already made a T8 tube with some 460 and 660 1W diodes, they're doing great with my African Basil plants.

 

[photonwave]

http://www.roithner-laser.at/All_Datasheets/Pricelists/roithner-pricelist-c-100111.pdf

Search for H2A1-H420. There are other 420nm LEDs in there also. Not cheap.

Ouch. Indeed, not cheap. Looks like I'm stuck asking around. They don't even offer it in the 1W power output that I require.

Time to sleep and dream of holding some 420s in my hands.

 

[Gomer]

Ouch. Indeed, not cheap. Looks like I'm stuck asking around. They don't even offer it in the 1W power output that I require.

Time to sleep and dream of holding some 420s in my hands.

I'll be at Photonics West tomorrow. I'll stroll through the exhibitor room and see if I see anything in that area.

 

[G12002]

It looks like ledsupply makes them. 1000 millicandelas at 15 degrees. Not sure about spectral distribution or shipping limitations.

 

[purduephotog]

The GE Vio LEDs use violet as their light source to illuminate their phosphor. From conversations with GE, they're using Nichia LEDs.

Hope that helps.

 

[purduephotog]

The GE Vio LEDs use violet as their light source to illuminate their phosphor. From conversations with GE, they're using Nichia LEDs.

Hope that helps.

Whoops. My apologies- 405 nm.

http://www.lumination.com/product.php?id=56

"The look that lasts. Vio™ LEDs provide all the benefits of solid-state lighting - energy savings, long life, robustness - and do something many white LEDs do not ... create exceptional light quality. Vio LEDs combine 405 nm violet chips with proprietary phosphors to create a natural white light that meets the high standards of lighting professionals. Vio LEDs feature minimal part-to-part color variation with a color shift of less than 75 kelvin over a 50,000 hour life. The result is a stable, more uniform warm white light, similar to a soft white incandescent lamp, that enables lighting designers to create a look that lasts."

 

[blasterman]

After begging and pleading with various manufacturers I finally have somebody in Asia that's willing to make some 440's for a reasonable price, but that's as short as they'll go. I need 420's for actinic in reef tanks, and just gave up.

SuperBrightLEDs has a 1watt 400nm Prolight.

 

[fyrstormer]

LEDs never produce just a single frequency of light. Surely the 440s and the 400s combined must produce enough 420 to make it worth bothering with.

As for growing plants in space, call me old-fashioned, but couldn't you just use a window with a gold-plate filter on it to let in real sunlight? Last I checked, plants like sunlight.

 

[blasterman]

440nm + 400nm (UV-A) doesn't equal 420nm.

440nm throws a lot of radiation for growth, but it's not very bright to our eyes. 440nm, and 420nm, also produce a lot of actinic effects, and to lesser importance they look cool.

420nm is common in fluorescent formats.

As for space, you'd need a big window, and keep it focused on the sun as you orbit. As I understand, this is impractical because it would bake that side of the spacecraft. Worked in 'Silent Running' though.