Problem with Green Laser

Hi all. I'm new in the forum . I just bought my new 5mw green laser pointer, those normal lasers that look like a pen, with a wave lenght of 532 nm. But the problem is , when I turn on the laser, it shows a strong green dot, normal for a 5mw laser, but suddently it decreases it's power to a weak green dot. That strong green dot doesn't last more than 2 seconds, I bought 4 AAA batteries yesterday and put 2 on my laser, but it doesn't get better, it stays the same... Can you tell what's wrong with my laser? Is it the temperature, because here in Portugal it gets chilly on winter days and nights...
Please help me!

If it's cold out, the laser will not lase very well, and batteries hate the cold as well. It could also overheat if not heat sinked correctly.

It also could be mode hopping, which can cause sudden changes in output. Go to a warm area and turn it on for about a minute and see what it does. Most green pointers have to "warm up" and take a moment to stabilize. It's possible you just have one that is really picky.

This is typical of cheap green DPSS lasers. They're like big diesel engines... hate the cold and require a bit of nurture to get them going. Keep it running (preferably in a warm room) for about a minute and watch it get brighter again. Once you take it outside though it will probably eventually cool down again and decrease in output.

the cheap 5mw also varies in quality, some can be super good, some can be real shit u never know really.

Ok thank you for the help!!

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