PHOTON-ENERGY DISSIPATION CAUSED BY AN EXTERNAL ELECTRIC-CIRCUIT IN VIRTUAL PHOTOEXCITATION PROCESSES

We consider generation of an electrical pulse by an optical pulse in t he ''virtual excitation'' regime. The electronic system, which is any electro-optic material including a quantum well structure biased by a dc electric field, is assumed to be coupled to an external circuit. It is found that the photon frequency is subject to an extra redshift in addition to the usual self-phase modulation, whereas the photon numbe r is conserved. The Joule energy consumed in the external circuit is s upplied only from the extra redshift.