LAX tower is reporting an "unauthorized laser event"(whatever unauthorized means)
I would speculate that "authorized laser event" would be a pilot's inadvertent encounter with a laser from a ground-based laser show that has been approved by whatever authorities do that sort of thing. In other words, a laser show like you see at a theme park such as Disney or HersheyPark.
During the warmer months of the Northeast US I constantly see NOTAMS warning of ground-based laser shows at or near theme parks.
With this thought, "unauthorized laser event" would be those done nefariously by scumbags with laser pointers looking for cheap thrills.