A novel phase-modulation to intensity-modulation (PM-to-IM) converter is proposed and experimentally demonstrated basing on a vertical-cavity surface-emitting laser (VCSEL). Comparing with the published schemes, in which the employed DI, FBG, OBPF or dispersion devices can only process a certain phase-modulated RF signal, the proposed scheme can achieve the conversion process in an economic and resourceful manner. To be the first one of achieving such PM-to-IM conversion process by a VCSEL, the feasibility of the proposal is experimentally demonstrated with an open eye diagram when it is employed to convert phase-modulated RF signal.