I doubt he will know for sure he was jammed. Laser diffusers do not "actively" send out signals. They simply make it more difficult for the laser light to reflect back off your vehicle. So the effective range of his laser is reduced. He may get an "error" or an "inconclusive" reading, but that could just as easily be because of other factors, like sunlight, light scattering, etc. As far as I know, it is only illegal to jam a radar signal. Diffusing lasers by making them more diffcult to reflect back is not against the law.