Andreev-reflected photons

We investigate theoretically the Andreev-reflected photons in a system with two vacuum-semiconductor and semiconductor-superconductor interfaces, taking into account the multiple reflections of a polariton at two interfaces. With the use of the Andreev reflection of an electron-hole pair in this geometry, we propose a novel generation scheme of a phase-conjugated photon with respect to the incident one. This mechanism is quite different from conventional methods using optical nonlinearities. The additional-boundary-condition problems are also reexamined from a viewpoint of an electron-hole picture.