Blue Laser "dirty" (or burned) diode ?

Hello. My name is Luiz and this is my first post.
First of all I´d like to thank for all the help I could find in this forum.

I bought a blue laser from china and it was working perfectly.
Today I realized that the light that comes directly from the diode is not uniform anymore. I don´t know what could have caused this.
It´s still able to focus with the lens and I didn´t notice any power loss when burning things.
I attached a picture that can clarify better the problem.

I appreciate any help.
Thanks !

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