Page 1 of 2 12 LastLast
Results 1 to 10 of 15

Thread: Creme of the Crop 445nm Diodes

  1. #1
    Join Date
    May 2009
    Location
    UCSB
    Posts
    708

    Default Creme of the Crop 445nm Diodes

    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.
    Click image for larger version. 

Name:	power.png 
Views:	59 
Size:	13.2 KB 
ID:	22440

    Here is a typical IV curve for one of the beasts, and IV data
    Attachment 22437
    Code:
    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.
    Attached Thumbnails Attached Thumbnails power dist.png  

    Last edited by krazer; 12-20-2010 at 00:08.

  2. #2
    Join Date
    Jun 2010
    Location
    Australia
    Posts
    3,730

    Default

    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.
    This space for rent.

  3. #3
    Join Date
    May 2009
    Location
    UCSB
    Posts
    708

    Default

    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?

  4. #4
    Join Date
    Jun 2010
    Location
    Australia
    Posts
    3,730

    Default

    Quote Originally Posted by krazer View Post
    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.
    This space for rent.

  5. #5
    Join Date
    Sep 2006
    Location
    Netherlands
    Posts
    1,425

    Default

    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.

  6. #6
    Join Date
    Oct 2006
    Location
    Cleveland, Ohio
    Posts
    2,334

    Default

    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

  7. #7
    Join Date
    Jun 2010
    Location
    Zweibrücken, Germany
    Posts
    606

    Default

    Quote Originally Posted by drlava View Post
    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.

  8. #8
    Join Date
    Sep 2006
    Location
    Netherlands
    Posts
    1,425

    Default

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

  9. #9
    Join Date
    Jun 2010
    Location
    Zweibrücken, Germany
    Posts
    606

    Default

    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

  10. #10
    Join Date
    Oct 2006
    Location
    Cleveland, Ohio
    Posts
    2,334

    Default

    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.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •