I have bought a laser module from China no-name at 100 euros. It's 532nm and 50mW. At the first start i put it on my house window when outside it were -4 -5 degrees Celsius. At the first 2-3 mins the laser point was a dot but after that it changed into 3 smaller dots in line. I swiched it off and put it in the house and turn it on again after a couple of minutes . After some time of working the 3 dots changed into a perfect dot and it stayed like that for and hour and passed. Afterall it was turned off a couple of times. Working the laser doesn't warm up at all. At a distance of 5m the diameter of the dot is 5mm.
Can someone explain me this dot changing thing?