OPLS laser keeps turning off and on!

[Laser Ben]

Yes your right Jeroen, its a coherent laser, Enermax power supply, and i think (looks like), a Kvant driver board.
Whats happening is, laser turns on for around 1 minute, then turns off for around 3 minutes. When the laser shuts down, there are a couple of red led lights, and a beeping noise coming from the driver board....

The red lights and beeping make me think it is a temperature fault. Are you sure the Lemo connector on the back of the laser is inserted all the way? Maybe try disconnecting it then plugging it back in.

When the laser is on, does it make full power? If it does, the LBO and birefringent temps are correct and it is the case temp.

[carlos3621]

Fun stuff!,
Well , it looks like you guys are right LaserBen and Jeroen, i was told by tech support at Kvant,
that its probably a bad TEC,
most likely scenario: 1 out of the 2 case Tec's bad.
so, it comes on, overheats because 1 Tec cant control temp, then turns off for a few minutes, untill case cools down.

btw, when its on, it will make full power.

[heruursciences]

Most likely the Laser pump diode Tec is bad. If the NLO xtal tec were bad you would not get lase, if the OPSL device tec were bad it would destroy itself after a couple cycles. most likely cause of failure is a cold solder joint either inthe connector leads to the TEC or in the TEC module itself.

[carlos3621]

the laser pump diode?
Im aiming towards the laser case / cooling tecs, is that different than the pump diode tec? , remember, it does lase at full power for about 1 minute, then cools down for around 3 minutes, and cycle repeats,
either way, its coming apart this weekend....
ill be doing resistance testing across the case tec modules to start....

[carlos3621]

If it is the pump diode tec,, then im in trouble...

[Laser Ben]

Most likely the Laser pump diode Tec is bad. If the NLO xtal tec were bad you would not get lase, if the OPSL device tec were bad it would destroy itself after a couple cycles. most likely cause of failure is a cold solder joint either inthe connector leads to the TEC or in the TEC module itself.

Chris, every single thing you said in that post is wrong, everything...

The diode and the OPS chip do not have a TEC, they are directly connected to the case which is cooled by a pair of external TECs. Neither are temperature dependent, the wavelength of the diode does not really matter as the OPS chip has a very wide absorption band.

The LBO is on a TEC which maintains it around 30C, it works just fine at room temperature, as it is not intended for non-critical phase matching.

The birefringent plate is also on a TEC and is maintained at a low temperature to fix the wavelength of the laser.

[sugeek]

If it is the pump diode tec,, then im in trouble...

You just got this laser, it it not still under warranty? If not Kvant has some explaining to do...

-Adam

[carlos3621]

still under warranty, but a pain to ship overseas. I have no problem swapping out a bad tec module,(if thats the problem), and they allready told me its o.k. for me to do so.
so i will try to first avoid a big mess with shipping overseas.....
i will not, however, open up any laser module, that would definately make me ship it to them for warranty repair

[pelosh]

Hey guys..whole case is beeing watched by us and it will be sorted. Most of the time we give customers option to sort problems themselves if they can and know how to. If not, we'll do it anyway.
It is just bit annoying that out of all Coherent modules we sold recently,only the one furthest from us goes wrong..

[Laser Ben]

still under warranty, but a pain to ship overseas. I have no problem swapping out a bad tec module,(if thats the problem), and they allready told me its o.k. for me to do so.
so i will try to first avoid a big mess with shipping overseas.....
i will not, however, open up any laser module, that would definately make me ship it to them for warranty repair

If that was the case, even Kvant would not be opening it up, it would go back to Coherent to get the laser replaced. Here's why:


See those little TECs? Those are under alignment critical components, and cannot be changed out without realignment.



Pelosh, who makes the drivers you use?