We study the interplay between lateral confinement and photon-induced processes on the electronic properties of illuminated graphene nanoribbons. We find that by tuning the device setup (edges geometries, ribbon width, and polarization direction), a laser with frequency Ω may either not affect the electronic structure, or induce bandgaps or depletions at ± ℏ Ω / 2, and/or at other energies not commensurate with half the photon energy. Similar features are also observed in the dc conductance, suggesting the use of the polarization direction to switch on and off the graphene device. Our results could guide the design of novel types of optoelectronic nano-devices. © 2012 American Institute of Physics.