Creme of the Crop 445nm Diodes

[krazer]

As a result of my testing experiments (see http://www.photonlexicon.com/forums/...881#post175881 for more details), I now have a number of 'exceptional performer' diodes which have been isolated and are ready for sale.

Due to the fact that I don't have a ton of these diodes, I am setting the price point fairly high, but I am open to offers/trades.

You are getting diodes in the top 0.5% of the lot, show by a red circle on my distribution plot.


Here is a typical IV curve for one of the beasts, and IV data
Attachment 22437

069046-22.iv
0.000000;1.793954e-04
0.100000;1.276665e-03
0.200000;2.033290e-02
0.300000;1.805660e-01
0.400000;3.498017e-01
0.500000;5.124351e-01
0.600000;6.698215e-01
0.700000;8.220427e-01
0.800000;9.733661e-01
0.900000;1.120332e+00
1.000000;1.264204e+00
1.100000;1.410333e+00
1.200000;1.547269e+00
1.300000;1.688392e+00
1.400000;1.817571e+00
1.500000;1.940899e+00

Note - These readings were taken in the stock diode array, mounted on a TEC to keep the temperature at 25C. The power was measured with a Coherent FieldMaster GS using a LM-2 probe, with the 1000x attenuator on it. The power was measured through the stock glass lens, and the cal on my meter is still in question, so take the absolute value of these readings with a grain of salt, but let me assure you--these diodes are smokin'

I am asking $75 a pop, which includes all paypal fees, and domestic shipping (via priority mail). For international, add another $15 for shipping.

[dnar]

Just curious. Your power/current graph looks wrong my a factor of 10 on the current scale.

So they state these are cream because of their efficacy?

Not sure you will get much interest here as most people using these diodes operate them at 0.5W - 1.0W and efficacy is of little concern. Beam quality is.

[krazer]

The binning is done based on efficiency, and thus the maximum power available.

Unlike the small emitter singlemode diodes (dvd, blueray diodes), the limiting factor for these diodes is current input, not optical power output--so the higher the efficiency the higher the output power. These diodes can put out over 2W of 445nm without breaking a sweat.

Per the graph, it looks like in resizing it the decimal vanished, I have since uploaded a replacement.

I also have the capability to add wavelength binning, would this be of more interest?

[dnar]

The binning is done based on efficiency, and thus the maximum power available.

Unlike the small emitter singlemode diodes (dvd, blueray diodes), the limiting factor for these diodes is current input, not optical power output--so the higher the efficiency the higher the output power. These diodes can put out over 2W of 445nm without breaking a sweat.

Per the graph, it looks like in resizing it the decimal vanished, I have since uploaded a replacement.

I also have the capability to add wavelength binning, would this be of more interest?

Wavelength binning would be interesting considering you test at 25c stable.

BTW, I think you should use the term efficacy instead of efficiency however.

[-bart-]

I think the proper term is efficiency, a dimensionless number (watts per watt). Manufacturers use the term slope efficiency too.

If the output was measured in candela, lumens or whatever efficacy would be the proper term.

[drlava]

These do look like unusually efficient diodes, so they will run cooler for a given power output, which is nice. The others are right, though, the longer the wavelength, the better. If these are very efficient AND long wavelength, you have gems

[Solarfire]

These do look like unusually efficient diodes, so they will run cooler for a given power output, which is nice. The others are right, though, the longer the wavelength, the better. If these are very efficient AND long wavelength, you have gems

How much longer can the wavelength get to make a noticeable difference? I’ve also bin selecting diodes for max efficiency but I can’t say that wavelength made a major difference. I intend on TECing them to best performance. I’ve been selecting them @ 1000mA and 22°C and the stray is pretty amazing, from 850mW to 1285mW (from what I’ve tested so far) but I haven’t quite tested as many as Krazer.

[-bart-]

An increase of 1nm will get you ~2% better visibility.

[Solarfire]

I don't know about that. Acording to the visibility table depending on wavelength it would be even less than 0.2%

Here's a cutout of the Table, with highest visibility @ 555nm = 100%

Wavelength +0 nm +1 nm +2 nm +3 nm +4 nm
----------------------------------------------------------------------------
430 nm 0.0273000 0.0283000 0.0294000 0.0304000 0.0315000
435 nm 0.0326000 0.0337000 0.0347000 0.0358000 0.0369000
440 nm 0.0379000 0.0388000 0.0398000 0.0406000 0.0415000
445 nm 0.0424000 0.0433000 0.0441000 0.0450000 0.0459000
450 nm 0.0468000 0.0477000 0.0487000 0.0498000 0.0509000
455 nm 0.0521000 0.0534000 0.0549000 0.0564000 0.0581000
460 nm 0.0600000 0.0626000 0.0653000 0.0680000 0.0709000
465 nm 0.0739000 0.0770000 0.0803000 0.0837000 0.0872000
470 nm 0.0910000 0.0949000 0.0990000 0.1040000 0.1080000
475 nm 0.1130000 0.1180000 0.1230000 0.1280000 0.1330000
480 nm 0.1390000 0.1450000 0.1500000 0.1560000 0.1630000
485 nm 0.1690000 0.1760000 0.1840000 0.1910000 0.1990000
490 nm 0.2080000 0.2170000 0.2270000 0.2370000 0.2470000
495 nm 0.2590000 0.2700000 0.2822900 0.2950500 0.3085700
500 nm 0.3230000 0.3384000 0.3546800 0.3716900 0.3892800
505 nm 0.4073000 0.4256200 0.4443000 0.4633900 0.4829300
510 nm 0.5030000 0.5235600 0.5445100 0.5656900 0.5869600
515 nm 0.6082000 0.6293400 0.6503000 0.6708700 0.6908400
520 nm 0.7100000 0.7281800 0.7454600 0.7619600 0.7778300
525 nm 0.7932000 0.8081100 0.8224900 0.8363000 0.8494900
530 nm 0.8620000 0.8738100 0.8849600 0.8954900 0.9054400
535 nm 0.9148500 0.9237300 0.9320900 0.9399200 0.9472200
540 nm 0.9540000 0.9602500 0.9660000 0.9712600 0.9760200
545 nm 0.9803000 0.9840900 0.9874800 0.9903100 0.9928100
550 nm 0.9949500 0.9967100 0.9980900 0.9991100 0.9997400
555 nm 1.0000000 0.9998500 0.9993000 0.9983200 0.9968900

[drlava]

With loosely regulated manufacturing that these are supposedly made with, a +/- 5nm shift is not unreasonable. Then , at the extremes, two diodes of the same output power would be about 20% different in visible brightness.