Getting a split beam out of the laser tube

During an alignment check I found I am getting two beams out of the laser tube. At the first mirror, they are approximately 2 mm apart. If this a faulty tube? The Orion Motor Tech K40 is only a couple of months old. I have done only a few projects. I have upgraded the controller to a 3D Cohesion Laserboard, added air assist and a chiller.

The most likely thing is that the tube has shifted into TEM01. This means that the tube is dead. Which chiller do you have? Have you always kept the tube temperature within limits? If so, I’d say go back to Orion and let them know that the tube died a premature death despite proper care.

Thank you all for the fast response. I felt reasonably certain the tube was bad. I have less than 5 hours on the tube. Water temperatures never exceeded 29C. The laser is in a climate controlled room so the 3000 series chiller should be adequate. I have contacted Orion Motor Tech. Hopefully they will stand behind their product.

Where did you get 29⁰C as an upper limit? That’s higher than I’ve seen as an upper limit from a reputable source. We give 20⁰ as a conservative upper limit generally:

Lightobject lists a more generous 18~24’C for their SPT 40W tube and their 35W K40 replacement tubes:

I haven’t seen reputable advice that a CW3000 is sufficient in a climate-controlled room.

Your advice is well received. The one time it reached 29 C may be the culprit. On average it stays around 24 C. So, I will rethink my cooling strategy. Thanks.

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Avoid this problem by adding a thermal controller in the interlock circuit that shuts down the LPS with overtemp.

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