They can and they do. Whether or not someone wants to take it to court, well that's another matter. California Vehicle Code, section 28150.The states cannot ban them. Radar jammers are banned because the FCC considers them interference devices. Laser on the other hand is not handles by the FCC but by the FDA. The states cannot control the airwaves because the FCC does and the states cannot control the spectrum that laser uses because the FDA does. The FDA does not have any rules against interference. Any state that tries will be justifying the law in court and will lose.
If someone takes it to court, CA will lose. You are talking about CA where they always try to push the envelope. CA is controlling what they don't have the power to do.