- Joined
- May 2, 2012
- Messages
- 151
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- 18
All of the beams on my class 4 greens are technically multimode not singlemode. The spots are not a clean singlemode TEM00 at any time. Since mine are always run under modulation (being turned on and off rapidly) instead of continuous output like handheld lasers their characteristics are different, but the beam profile is never 100% stable on any of them. It's just the price you pay for inexpensive power. For average hobbyists and all laser shows there is no real need for perfect beams though..
Also, being TEC cooled helps show modules like mine stay more stable than passively cooled modules.
Here's an example of a typical profile for my lasers:
you can see that the spot is round, but the power distribution across the spot is uneven, with hot and cold spots. Yours should be similar to this once it warms up and stabilizes.
An oval profile isn't a problem at all, but if the beam profile never consolidates, remaining clearly separate beams even after warmup then you have a warranty claim. It should be noted that modules like yours used in handhelds have duty cycles (the length of time you can run the laser between cool-off periods) so I wouldn't run it much more than a couple minutes at a time. After a few 2-3 min. runs the crystals inside the laser should be nearing their optimum temperature, so your "warm-up" would consist of several 2-3 minute runs separated by 2-3 min. of off time. My show lasers aren't guaranteed to be at peak stability until after 15 minutes of run time.
Once again, thanks for sharing your knowledge! Since i can´t run it much longer than 2-3mins (i´ll try to go a bit further with additional cooling elements), i am not sure if my module will consolidates. But i will test it as soon as posible.
And because my aim is a good divergence, i am not sure if the "oval" dot will affect the divergence!? What do you think?
The supplier (David) told me, he will replace it if i am not satisfied with the output. I got to decide that as soon as possible.
Thanks so far!
Greets from Austria,
Christian