"The Blues" - 449, 460, 478, 495

I've been wanting to do a comparison of my diode blue builds for a while. I was hoping the 4-laser shot would turn out a bit better, but it's a start, I may try again in the future. Practically speaking, my 495 is such a low power build that it would be near impossible to get it to show up when next to the others. It was hard enough to position them all at the correct distance from my spectrometer fibre so that I could catch them all on one reading:



Picture from left to right. These are completely un-retouched photos.

449nm @ 2.5 W (typical 9mm multi mode)
460nm @ 4.5 W (Nichia array extracted diode, possibly closer to 465nm by time of photo)
478nm @ 800 mW ("edge-driven" 462)
495nm @ 10 mW (single mode)



Here's a slightly better shot, taken in RAW. However, there's no getting around the fact that the camera sees the 449nm and 406nm almost the same way. The dramatic difference (in person and on film) is the jump to 478nm:



Here's an unretouched photo of the 449nm (typical 9mm multimode) next to the 478nm ("edge-driven" 462):



And a solo of the 495nm (in a beautiful eghemus host):

Holy hell are those 478nm and 495nm lasers just lucky bins from the the new 462 diodes?
how does the 495 look vs a 473?. It must be very cyan.

joeyss said:

Holy hell are those 478nm and 495nm lasers just lucky bins from the the new 462 diodes?
how does the 495 look vs a 473?. It must be very cyan.

Click to expand...

Actually, the 495 vs the 473 ends up looking very green. The 495 was something different entirely. It's a single mode, and it was just a very lucky break a couple years ago (much like any of the other 495s out there in hobbyist hands). Found someone that had one, and was willing to part with it.

The 478nm is a combination of lucky bins (I grabbed a bunch of the 462s from a couple sources, early on) and my "Edge Driver", which is a buck designed for the purpose of safe-ishly pushing 462s right up to within 3% or 4% of their actual death current. They hit a power kink at around 2.2A (beyond which the output power starts decreasing with current) and then a true death kink at around 2.95A (beyond which the power drops very rapidly and they die). The Edge Driver keeps the current locked very precisely at 2.85A throughout the whole duty cycle and produces a very clean output so that there isn't any significant ripple to create problems (important, since the diode is being run so close to the death kink). I talked about it a bit here. If I had another decent host, I'd try my luck at 2.9A (I still have one more high binned Nichia 462 left).

Nice man that 495 is just gorgeous! One thing you cpuld try, for just a color comparison, is defocus them slightly on a dull colored surface, then slightly defocus your camera- it makes for a blooming effect that helps even out one laser overpowering the others.

Beautiful pictures and comparison! Would rep if I could. I'm particularly jealous of that 495nm build.

Hey RHD, did you ever find any "445"s which bin quite low in wavelength? If so, what's the lowest you've found. I've always wanted something in the 425-435nm range. (not that I'm able to pursue it now financially, but a guy can dream, can't he?).

I doubt you would get a 445 that low. You may get a 405 up to 420, but any higher would be extremely unlikely. AFAIK, getting a 405 diode thats >410nm isn't that uncommon.

Sigurthr said:

Hey RHD, did you ever find any "445"s which bin quite low in wavelength? If so, what's the lowest you've found. I've always wanted something in the 425-435nm range. (not that I'm able to pursue it now financially, but a guy can dream, can't he?).

Click to expand...

Nope. Sadly not That's part of the reason I wish we could find nichia multi mode 405s, to try to push them up toward the 420 range (can't push single modes)

For what it's worth I've spent a lot of time trying to find a source of 420nm laser light for my lab job and it seems like the only easy option is to just buy a 420nm laser diode for $1k. The lowest 445nm diodes are around 435nm from the a140 projectors and those are fairly rare...there is a nice thread on PL showing the statistics of the WL/power of the a130/140 diodes.

Dang 495nm?? :drool: I've missed a lot lol

The blue cutoff with digital CCD sensors is typically 450-455 (dominant) so digital cameras of any sort really have a hard time rendering the color of lasers below 462nm as anything other than purple.

Difference between 445, 462, and a mutant 462 I have that's running closer to 470nm is pretty staggering. The 445's look 'muddy and dim' by comparison.

hey, that's a hell of a collection right there. Nice to see some uncommon diodes and WLs.

I hate to sound unsatisfied but I'm curious to see what advancements they will make available at a feasible price in the next coming years in the 400-500nm wavelength. The 462 was really a blessing. Mine metered 471nm @ 2.6A. The days of the high priced DPSS 473 seem to be over? If you are willing to over look beam specs.

If you are willing to risk the push and don't mind the greater divergence it really is an option.
Great work RHD,
Jefferson

I can only imagine the difference from 462nm to that 478nm!

I have a low WL 445nm and a high WL one and you can easily see the difference on the beam or on the unfocused dot.

blasterman said:

The blue cutoff with digital CCD sensors is typically 450-455 (dominant) so digital cameras of any sort really have a hard time rendering the color of lasers below 462nm as anything other than purple.

Difference between 445, 462, and a mutant 462 I have that's running closer to 470nm is pretty staggering. The 445's look 'muddy and dim' by comparison.

Click to expand...

somehow my i phone camera picks up 473 as purplish yet 3 watts of 445 looked like a blue beam. Maybe cause it over loaded the camera due to the beam making smoke from hitting a piece of wood.
445nm looks like a weird color. It's like someone mixed a 473 and 405.
I personally see a more violet beam and the dot looks different than the beam. Like royal blue.

I wonder what nm real blue is. mid 460?

473 looks like blue at first but when you sit in a dark room after awhile you notice a slight greenish tint to things if it's the only source of light in the room.

same thing happens to me with 532nm , but with a yellow tint and it's not my mind cause i compared it to a 520nm and i saw that yellow tint in the 532 right away.

Times like this when i hate being colorblind lol...

joeybab3 said:

Times like this when i hate being colorblind lol...

Click to expand...

Picked an odd hobby mate.

I've been eyeballing that 495 in your sig for some time now. Nice to finally see it.

I've wanted an isolated, higher powered ~500nm source ever since seeing 496.5 and 501.7 on my ions..

EDIT: If you ever get around to cooking up another handful of those edge drivers, I'd be interested in one.