Modifying Q-switch driver for external modulation

[aijii]

I don't think so. But since there is no way to hold-off the beam, there is no way to build up a giant pulse, so FPS isn't necessary anyway.

actually, low RF mode on our scopes must be dumping full RF power to the aom, as when we jumped the ALE on the weekend we noted that low RF mode actually extinguishes the laser output...

Not sure if this varies from model to model though.

[Simon]

actually, low RF mode on our scopes must be dumping full RF power to the aom, as when we jumped the ALE on the weekend we noted that low RF mode actually extinguishes the laser output...

Not sure if this varies from model to model though.

Low RF mode selects CW beam on my laserscope as is the factory setting but you can retune it do this but FPS is still an issue for modulation.

[DMills]

As standard, low RF introduces sufficient loss to limit the CW power to well under a watt.

IIRC it was used for the aim beam when running KTP mode (The HeNe was the aim beam for the IR mode).

Regards, Dan.

[aijii]

That makes sense. We had the lamp at low power (20 amps or so). If what you say is correct, then its quite likely that the qswitch was dropping the gain enough to kill lasing.

So maybe if we'd have had more juice running through the lamp, we'd see some green in low rf mode.

[andyf97]

can anyone shed some light on this.

I have just completed a setup of a cooling unit, power unit and a head unit and all seamed perfect.

Now that i don't have the noisy cooler fans, pump or ale fans near the head I start to notice some odd sound. When the lamp comes on it is OK but when I crank up the power to 25% and higher in CW mode this noise starts, its like a creaking sound but it is uniform and does not stop, I thought maybe this is trapped air being compressed by the minor raise in temperature. Any clues?

Also I started to see in CW mode the beam is not stable, it is flickering almost like there is a bad connection. It seams to be going in and out of modes like from Temoo to Tem11 and very randomly.

Andy

[Laserman532]

can anyone shed some light on this.

I have just completed a setup of a cooling unit, power unit and a head unit and all seamed perfect.

Now that i don't have the noisy cooler fans, pump or ale fans near the head I start to notice some odd sound. When the lamp comes on it is OK but when I crank up the power to 25% and higher in CW mode this noise starts, its like a creaking sound but it is uniform and does not stop, I thought maybe this is trapped air being compressed by the minor raise in temperature. Any clues?

Also I started to see in CW mode the beam is not stable, it is flickering almost like there is a bad connection. It seams to be going in and out of modes like from Temoo to Tem11 and very randomly.

Andy

in cw mode it wont be stable - seems normal

is the sound coming from the yag head block? (yag lamp cavity) Depending on what this problem is it might fix the above problem.

[andyf97]

Hi Pat,

Nice to hear from you, been ages since we exchanged any messages. Wish you a merry Christmas and wonderful new year.

The sound seams to come from the lamp housing/cavity and overnight i was trying to think how to describe this sound. Its something similar to thousands of popcorn being created, the sound is soft and not erratic like popcorn more like white noise and it comes when I apply over a guess of 25% of current.

A point about stable CW, could that also be effected by the KTP temp not being stable? I am not 100% sure but think the Oven controller might not be perfectly setup. A possible cause?

One again Merry Christmas Pat.

Andy

[Laserman532]

Hi Pat,

Nice to hear from you, been ages since we exchanged any messages. Wish you a merry Christmas and wonderful new year.

The sound seams to come from the lamp housing/cavity and overnight i was trying to think how to describe this sound. Its something similar to thousands of popcorn being created, the sound is soft and not erratic like popcorn more like white noise and it comes when I apply over a guess of 25% of current.

A point about stable CW, could that also be effected by the KTP temp not being stable? I am not 100% sure but think the Oven controller might not be perfectly setup. A possible cause?

One again Merry Christmas Pat.

Andy

Stability- the laser is only mode stable when q switched and aligned properly. CW it will act weird at different current levels for different lasers, too many variables.

Other question answered in PM (please do not publish) only repeat to reputable operator / owners.

[andyf97]

Wobbling beam,

I can stop the wobble by adjusting the KTP but I end up with two beams with a bit of fuzz between.

No matter what i do i keep ending up with two beams side by side or wobble, i don't have the heater connected up, could the lack of the heater be the main cause?

[Laserman532]

andy, you have to start with that...silly