trilights 532nm 200mw Ebay

[laser_freak]

I have almost exactly the same laser from the same ebay seller (different power output), however mine has horrible analog modulation. Is yours at least acceptable?

[laser_freak]

Bumpity bump bump

[polishedball]

been lazy thanks for the reminder, will get on this in the next couple days.

[goninanbl00d]

Apologies in advance for the necrobump.

The 150+mW units have since been pulled, this wasn't the only quality control issue, it seems.

Apart from that, there's the analog modulation issues. Apparantly, it's closer to PWM than analog, so when modulated, the output is pulsed, insteading of drop linearly (EDIT: OK, word structure fail. But I won't fix it so you can all see me fail and laff.) when a modulation signal is detected.

I've got one of the 150mW analog versions in the mail, I'm curious to see how bad the analog modulation really is.

[dnar]

My LPM arrived the other day, with an IR filter in place the TriLights 150mW TTL measures 212mW. I then tweaked the TEC adjustment and LD drive current with 5 minutes gaps and recorded results. I found the optimal setting provided 265mW. Not bad!

Funny this is, the drive current adjustment is down 5 whole turns, the TEC is down 1/2 turn from stock. Stable at 265mW over a one hour period. Runs a little cooler also.

[goninanbl00d]

My LPM arrived the other day, with an IR filter in place the TriLights 150mW TTL measures 212mW. I then tweaked the TEC adjustment and LD drive current with 5 minutes gaps and recorded results. I found the optimal setting provided 265mW. Not bad!

Funny this is, the drive current adjustment is down 5 whole turns, the TEC is down 1/2 turn from stock. Stable at 265mW over a one hour period. Runs a little cooler also.

Mmm, I'm not surprised. From what I've heard there's never been a single report of a unit turning up underspec.

I'd guess the pump diode's working much harder than it'd have to, though. It *is* a C-Mount, and it'd make sense to drive them as hard as possible. Having said that, the crystals are probably at the point where they're just going "Nope, no more, here, have the rest as IR". I suspect a 808-reflective OC may improve things to a degree, or make the crystals explode. One of the two

When I get my grubby little hands on an LPM, I'll be sure to tune mine too, and see how it goes.

[goninanbl00d]

Sorry for the double post.

But I got it running, and much to my surprise, it isn't true analog, but it's actually PWM.

At slower scan rates, you can actually make out the invididual pulses.

I'll get some photos as soon as I can. But meanwhile, a warning.

STAY WELL AWAY FROM THESE ANALOG LABBIES, OR ANY OTHER ANALOG LABBY THAT LOOKS REMOTELY LIKE THIS UNIT

I've contacted the supplier, we'll see what becomes of it.

[dnar]

I think it's a classic case of "you get what you pay for".

[badger1666]

i dont think dpss lasers do pwm the pulses you are seeing are a case of it
jelly beaning common in cheap lasers and somtimes more expensive ones
you can tune it out , with a tweek of the tec cooling

[goninanbl00d]

i dont think dpss lasers do pwm the pulses you are seeing are a case of it
jelly beaning common in cheap lasers and somtimes more expensive ones
you can tune it out , with a tweek of the tec cooling

No, it's actually a driver issue.

A proper analog laser doesn't do that. I've seen first-hand a proper green ramping up from 0V and back down again. At no point was the scanning output pulsed in any way.