Hi all, would appreciate some advice here

Been looking into lasers for permanent hair removal and whitening as my underarms are dark due to shaving during young age and changed to waxing recently.

I've come across something called diode laser, is it good? It's around the same price with Ipl in my area tho, what's the difference between diode and spl and ipl??

And there's another whitening laser treatment called pico plus, anyone heard of that?

Thanks!!