Laserwave 1W 520nm green diode module - part 2 - powering up and measuring

[bridge]

Aha, I know some manufactory marked their blue and 638nm <1mrad here, but factory is can't match, because they only test the center brightness part, we can compare side by side. look like greenalien will do some side by side test, that's good, thanks.

[badger1666]

Why expect 1 mrad , hobby guys have no problem getting 1mrad out of reds and blues and this new green is ment to be as good as the 445 nm so why do manufactures have trouble doing it ??

I don't know why you're expecting 1mrad divergence - Laserwave quote < 2 mrad on their website, and my tests confirm that this is the case.
When I've finished installing the new module in my projector, I'll do a side-by-side comparison of the new green against a Kvant red (array of 638nm) and a Kvant blue (Single Nichia 445 nm, from when they cost loadsa money, before people started harvesting video projectors...). One thing I can say - compared with my Viasho DPSS green 1W that's just come out of the projector, the new diode green is significantly brighter.

[bridge]

Hi Badger1666, your divergence is strictly <1mrad? you also in UK, maybe you can do side by side compare with our lasers.
at least, we compare with others products who mark <1mrad , factually it is the same or large than our beam.
our 520nm had with correct collimation.

Why expect 1 mrad , hobby guys have no problem getting 1mrad out of reds and blues and this new green is ment to be as good as the 445 nm so why do manufactures have trouble doing it ??

[daction]

Heya You said that below 1.28 volts that it goes led. does that mean that it has no beam suppression ?

[greenalien]

Under analogue control, there's no beam output with a control voltage below 1.28 volts - the module just glows internally - above that voltage, the module produces a beam. This figure is likely to drop a little once the module has warmed up for a while. I'm not sure what you mean by 'beam suppression' - at 0V, there's definitely no beam!

[edison]

So bassically the first 0-1.28V it stays in threshold mode and is not lasing. The question is at what voltage it would be at max power. Then you would know the bandwidth. The smaller it is the less number of color variations you can make.

[MIIKKKLLLL]

So bassically the first 0-1.28V it stays in threshold mode and is not lasing. The question is at what voltage it would be at max power. Then you would know the bandwidth. The smaller it is the less number of color variations you can make.

On the other hand, it's always a advantage to reach full power @t 4.6-4.7V (not exactly 5.0V) to counteract the voltage losses through the ILDA cable + driver. You lose maybe some color steps, but ensure you reach full capacity of the module when needed.

[greenalien]

The question is at what voltage it would be at max power.

See the graph in the first post

Then you would know the bandwidth. The smaller it is the less number of color variations you can make.

Not true. The number of colour variations you can make is effectively infinite, as it's an analogue control signal. The thing that limits the number of steps is the number of bits in your D to A converter - with an 8-bit converter, you will have 256 colour steps; with 12 bits you will have 4096 steps and with 16-bit you will have 65536 variations. Good software should let you set the start and end points of the conversion so no bits are wasted at the top and bottom of the voltage range.

[edison]

I expect that people use "good" software and i,m well aware how a dac works.

If i sell a module thats starts to lase at 1.28V then i,m seriously in trouble that for sure. Theoretically a module should start to lase just above 0V and at 0V it should be totally shut off. But that of course is in theory. In my opinion it should start to lase at mv level but then again who i,m i to tell other manufacturers how it should be

[daction]

Sounds like a job for stanwax colour correction board. Funny thing is that I thought that with dumping the dpss green you could avoid colour correction board.