Deductive answer: The laser energy will be absorbed by the epidermis layer of your scrotum, since that’s how laser defoliation works. Therefore, very little laser energy will penetrate to the specialized functional areas of your gonads. This assumes, of course, that the laser isn’t overpowered and the technician shuts off the laser after the follicle has been vaporized.
Inductive answer: When the laser was invented, scientists got government grants for exploring the effects of shining lasers on everything from adenoids to zits, including, I’m sure, testicles. It appeared to many as if coherent light would have some magical effect that regular light doesn’t.
At least, this was plausible enough for my Uncle, a MIT Chemistry professor, to get a decade-long government grant in the 1970’s to induce tumors in lab mice, make little sadistic mouse racks out of clothespins and plexiglass upon which the mice were clothespinned in a spread-eagle configuration, and the output of a $100,000 (at the time) HeNe laser directed upon their affected areas for hours at a time.
Of course, this resulted in nothing at all. But hey, it was lasers, so it was cool. And it involved cancer. So it was important research.
In other words, if there were any deleterious effect of shining Nd-YAG emissions on your scrotal area (other than, of course, perforation and ablation), I’m sure someone would have noticed by now.