You are not crazy. Laser and light treatment have been shown in the past to affect hair growth. Usually, they are used for hair removal and reduction. There are occasional anecdotal stories of hair growing thicker after laser hair removal procedures, especially in the past with older generation lasers. IPL and fotofacial procedure is not new and have been around for several years.
Some forms of IPL machines are used for hair removal. As with any laser, they are usually not great for removing fine "peach fuzz" hair. It would be extremely unlikely for you to have your fine hair burned and then grow thicker. Talk about your fears with your treating physician. If you anticipate great improvement from IPL, you should go ahead with it, since the risk of hair growth is minuscule.
