I've bought a green laser some days ago, just got it today.
It's pretty bright for a while (<10 secs), then it's brightness suddenly goes down to about half, without any fade. It's not mode-hopping.
Is this normal?
Most pen lasers do this. They have poor heatsinking so they heat up fast and the output drops. Try shining the laser through a magnifying glass to check for mode hoppping. You can also trying asking wicked's customer service