| abstract |
The present invention relates to a novel and useful way of generating a strong source of doubly or multiply entangled photons. To generate a high flux of such photons we propose the use of a parametric process, or a set of simultaneous parametric processes, in conjunction with laser-type action and nonlinear optical processes in an optical cavity. This can be achieved via an optical-system configuration in which two, three or more processes take place simultaneously: the generation of light by stimulated emission or other means from an active medium in a cavity; the nonlinear-optical production of higher optical harmonics in the same or in a n auxiliary cavity; and the generation of spontaneous parametric downconversion in the same or in an auxiliary cavity. Laser action can be achieved via the usual stimulated-emission mechanisms associated with a pumped active medium in a cavity or, more generally, via schemes that produce laser light without population inversion by virtue of quantum-interference effects or other optical processes. The generation of high-flux entangled-photon beams can take the form of continuous wave (cw) or pulsed light, the latter can be achieved by means of any number of mechanisms including gain switching, cavity dumping, Q-switching, mode-locking, or any combination thereof. Parametrically downconverted radiation generated in the manner described above is expected to have novel, unusual, and useful statistical, entanglement, and hyperentanglement properties. It is expected to find use in a large number of applications, including new forms of optical measurements; new forms of optical spectroscopy; new forms of quantum imaging including entangled-photon microscopy, spectroscopy, and display; quantum information; as well as offering new ways of examining quantum paradoxes. |