Good source for the DVD diodes?

[p1t8ull]

Photonic have 82 in stock and 100 on order.

If you want one, or some now, there's a new thread in the GB forum to help either get a few (Photonic have a min order of £150+VAT) or get a discount for larger numbers:
http://www.photonlexicon.com/forums/...ead.php?t=2180
If you are unsure about my results, wait for others to test and report back.

Pit.

[p1t8ull]

it seems all three that have been tested, are now randomly polarised

Scratch that polarization issue, it seems my new diode mount's insulation was breaking down, causing the problem.

Pit.

[The_Doctor]

Ok, I have one, sent to me for testing.
I've put it in a module I made from my old design, no modulation, no TEC, but very strict soft start and surge suppression, so if it dies, it won't be from static or line borne surges. (I can scoot around the floor in my socks charging up and letting a spark hit this case repeatedly without killing a diode, which is why I chose this, it's a reliable test support).

I set a current of 266 mA (nominal, is based on 1% tolerance 4R7 in an LM317T constant current regulation circuit, not measured). First, I tried a Rohm RLD65PZB5, which put out 121 mW. Then the Opnext/Hitachi HL6545MG.

It's a stunning start, 220mW! Lasercheck at 658 nm for each test. Actual wavelength not known, but I'm finishing a postponed final PCB layout of a thermopile gain stage I made for a Scientech sensor I got off eBay. I'll calibrate that with a Lasercheck and a 532 nm DPSS with good IR filtering so I can get power measures without need to know wavelength.

Viewing the beam profile spread across a matt black surface, the specularity is pin-sharp, crystalline, suggesting a clean stable resonance. This would look vague if overdriven too much, as the energy forces a broadening of linewidth, specularity appears milky if this happens, Opnext/Hitachi diodes show this, not sure of Rohm yet, not pushed one that hard. I've often pushed diodes to this point, and if you pull back within minutes, lifetime is usually unaffected.

Reflections off the Lasercheck ND filter do not kill the diode. I think a diode should be able to take those, at all times during its life, if it can't it's being pushed too hard. I'll check that again during the next two days or so, if it makes five days without sensitivity increasing, I'd put serious trust in these diodes.

This one has a slightly annoying diagonal lobe of spilled light from I know not what, but the spot is very tight, slightly better than the Rohm diodes (which are still extremely good, with next to zero light spill, too). The pinout is the same as Rohm's, and the focus did not need changing between diode tests, so it seems that any condition that was optimised for the Rohm diodes is one you can plug one of the HL6545MG's into without change, except that you should expect the output to nearly double for the same current. If I hadn't got my 200 Rohm's as cheap as I did, I'd be seriously annoyed, but I'm still happy, I really did get them cheap, and I don't know what the long term for these HL6545MG's is yet. I will raise the drive power, but not for at least a week of constant uptime at this output. My guess is they'll do a lot more because they seem to still be on the steep safe slope for current vs power out. The big question is how long they'll do it for.

[aijii]

Nice...

We should have a competition for who can combine the highest number of these things...

[Astroguy]

Has anyone tried one of the Sony diode?

Sony high power visible laser diode at 670nm

The Sony SLD 1332V is a high-power (500mW), high-brightness, visible laser diode suitable for use in machine vision, therapeutic medical lasers and measurement applications. It offers 500mW optical power output at a wavelength of 670nm, with internal monitor photodiode in a 9mm package.

The SLD 1332V has an AlGaInP quantum well structure which enables it to achieve the high brightness needed for machine vision applications used in autonomous vehicles, industrial inspection, medical imaging, remote sensing, surveillance and transport.

The high optical output power of 500mW at 670nm in a 9mm can type package also makes the SLD1332V particularly suitable for use in therapeutic medical lasers.

The SLD1332V has an operating lifetime of MTTF 10kh at 500mW (at an operating temperature of 25°C), operating wavelength of 670nm, optical output power of 500mW and laser diode reverse voltage of 2V.

It requires a negative power supply (N-type) and has an operating temperature range of -10°C to +30°C.

http://www.photonic-products.com/pro...y_visible.html

[The_Doctor]

You forgot the bit about it being multimode with a large 'stripe width'. It sucks for making narrow beams with. I used to think it could be fun but I'm glad now I never spent money on one. I just got TWO HUNDRED Rohm diodes for what ONE of those wretched beasties would have cost me. I could have spent the same amount on optics in a futile effort to get a decent beam out of it too.

[stanwax]

plus in terms of visible perception 670 nm is (about) half as bright as 658nm. So 200mW of 658nm wouldnt look much different to half a watt of 670nm.

Rob

[Astroguy]

It can be cooled with a TEC and run a 660 but I did not know it was multi mode and cost so much.

[steve-o]

plus in terms of visible perception 670 nm is (about) half as bright as 658nm. So 200mW of 658nm wouldnt look much different to half a watt of 670nm.

Rob

Does that mean that a 635nm would look 3-4X as bright? -or the same brightness for 1/3 the output power?

[SenKat]

Now to find some small, efficient TEC to fit into a tiny holder for these pointers....Mmmmmmmmm....