Blue laser 445nm

[p1t8ull]

Group buy for 445nm Diodes!!!

How much are 445 diodes?

Here is a link of a 50mW single mode 440nm doide: http://www.nichia.com/specification/ld/NDHB510APA-E.pdf

They also have 500mW multimode diodes http://www.nichia.com/specification/ld/NDB7112E-E.pdf

They were about $3k for the 500mW 445nm...
They also do a 1w version of it now but no doubt it'll be expensive

[aijii]

They were about $3k for the 500mW 445nm...
They also do a 1w version of it now but no doubt it'll be expensive

We've looked into group buy quantities. You don't really save much for tens and twenties. They are still up there in the thousands.

You can always mix a bit of green iwth the violet to give you blue though....

BTW, I'd be interested to know how it is that medialas get 600mw of 445nm after optics out of a 500mw rated diode.

[Pitts]

Thanks for all the feedback... an interesting point none the less.


As to price..

I don't know what the actual diode sells for but the complete OEM module sells for 1950.00 Euro's for 500mw (1 diode) or 3950.00 Euro's for the 1000mw (2 diodes)..
This one thousand Euro difference including the work and hardware may suggest the diodes are now somewhere less than 1000 Euros a piece..?? by the way as of two minutes ago 1.00 Euro = about 1.366 US $....

By the way the 6 watt one uses 12 diodes and is a mere 21,800.00 Euros.. any takers ?

I guess that may suggest that the prices must be coming down as they still have to build it along with other components..

Cheers

Ray
NZ

[Zoof]

I guess that may suggest that the prices must be coming down as they still have to build it along with other components..
Ray
NZ

I remember the 405nm diodes being up in that range - and how much I needed one then

Having given the whole color mixing a bit more thought:
We should really look at the individual cone responses to R,G and B instead of the overall luminosity. Like AIJII says, you can always mix a little green with the 445/457 to make it bluer/brighter and equivalent to 473's color. Looking at the chart above (may not be the best one), the blue cone response for 445 is twice that for 473....
Mixing with green 445 will give twice as much "473 color blue" as with the same amount of 473 without mixing green (but the same tone of blue).
That was what the Arctos comment was about, I suppose.

There are so many charts out there for R,G,B cone responses with significant differences. Which one to use?

[mccarrot]

Hi Zoof,

Wat about mixing a little bit of green with 405nm? will this get you also a much brighter blue?

[Zoof]

Hi Zoof,

Wat about mixing a little bit of green with 405nm? will this get you also a much brighter blue?


Ps ik heb meester Einstein (Hugo) van het weekend weer aan het werk gezien op Awakening, 9 lasers + 8 spiegelbollen op het podium... geweldig... als je filmpjes wil...

Hey Mccarrot,

good to see our small country below the waterline being represented more and more, here on PL !

I have no experience with 405 (or 445) so this is all prediction based on those charts. But yes it should work. Look here for actual results: http://www.photonlexicon.com/forums/...ead.php?t=5460
I'm not sure about the tones of blue achievable, there might be a `spectral gap' there but we should ask thesk8nmidget.

445 seems nice because it is close to the peak of blue cone response.

Do you have those movies online somewhere?

cheers!

[tocket]

I remember the 405nm diodes being up in that range - and how much I needed one then

Having given the whole color mixing a bit more thought:
We should really look at the individual cone responses to R,G and B instead of the overall luminosity. Like AIJII says, you can always mix a little green with the 445/457 to make it bluer/brighter and equivalent to 473's color. Looking at the chart above (may not be the best one), the blue cone response for 445 is twice that for 473....
Mixing with green 445 will give twice as much "473 color blue" as with the same amount of 473 without mixing green (but the same tone of blue).
That was what the Arctos comment was about, I suppose.

There are so many charts out there for R,G,B cone responses with significant differences. Which one to use?

Color mixing is a complicated matter, as I discovered. The easiest way to find out what color a given spectral power distribution has is to plot it in a CIE xy chromaticity diagram.

If you mix equal powers of 445 and 532 you'll end up with something that resembles the argon blue-green rather than a 473 icy blue. On top of that, brightness is not additive.

I have a matlab script that plots the color in a chromaticity diagram, but I have not yet managed to add a brightness functionality to it.

Wat about mixing a little bit of green with 405nm? will this get you also a much brighter blue?

Mixing for example 15mW of 532nm with 200mW of 405nm gives a blue, but its saturation will be much lower. The brightness should be similar to that of 120mW of 473, but this I'm unsure about.

See the diagram below for the hues possible by mixing 405+532 (represented by the line):

[mccarrot]

Mixing for example 15mW of 532nm with 200mW of 405nm gives a blue, but its saturation will be much lower. The brightness should be similar to that of 120mW of 473, but this I'm unsure about.

Hmmm interesting, 200mW of 405nm and a little bit of green (you give your big green a few mV from the blue signal to ad some mW of green) is Way cheaper compared to 100mW blue, and the losses on the galvo mirrors should much more less if I'm correct.

If te above statement is true I'm seriously thinking of adding a blu-ray to my 100mW 473nm blue, then I will end up with 200mW blue

[Zoof]

It such a shame the computer screen doesn't do justice to the CIE diagram

The CIE diagram has been much discussed here. It is easy to find the colors achievable (gamut) with any set of primary colors. It does not, however, show the intensity in mW needed to achieve the colors. What Arctos was talking about cannot be read off the CIE diagram. The underlying math should allow computation of brightness (Y) since it is basically a graphical representation of the eye's cone response. I'm interested in seeing what you come up with in Matlab.
Does your book "The science of colors" have a good diagram of the absolute cone responses? (would you share it?)

[tocket]

Yes, computer displays really show their weakness here. Even using only 3 colors laser display technology can significantly improve the gamut. I'm eagerly awaiting laser TV.

To get my plot the tristumulus values (X,Y,Z) must be calculated. These are then normalized and plotted. The Y value is by definition the luminance. However, luminance and brightness are not the same.

Here is a quote from the book regarding brightness:

Brightness of an unrelated color is the perceived level of light emitted by the source. Brightness is not linearly related to radiance, an energy-based unit, even for light of a fixed wavelength. The relation between brightness (Ψ[Br]) and stimulus radiance (x) at wavelength λ is approximately a power function with exponent 0.33 (Stevens and Stevens, 1963): Ψ[Br] = a[λ]x^0.33, where a[λ] is a proportionality constant that depends on wavelength. Values of a[λ] do not merely relate energy to the luminous efficiency of photopic vision; if they did the equation for brightness could be rewritten in terms of stimulus luminance (L) rather than radiance, Ψ[Br] = aL^0.33, which would imply lights of different wavelength but equal luminance would appear equally bright. It is well known, however, that they do not.

So now I need to find tables of this a[λ]. Another thing to note is that brightness, unlike luminance, is not additive. What is especially interesting here is something called brightness enhancement. Again, from the book:

For example, define one unit of 422 nm light as the luminance that matches the brightness of a fixed achromatic standard. Similarly, define one unit of 521 nm light as its luminance that matches the same brightness standard. Then mix the 422 and 521 nm lights, with the luminance of 521 nm at half of its matching level (that is, at 0.5 unit). The mixture field and the fixed standard will match in brightness with 421 nm at about 0.35 unit, well below the 0.5 value specified by brightness additivity.

It is interesting because it implies that mixtures of violet and green appear brighter than is suggested by their luminance.