Abstract: An EL element and a laser luminescent element capable of emitting ultraviolet ray with high wave length purity. The ultraviolet electroluminescent element characterized in that: a thin film made from one of polymer and oligomer in which elements selected from Si, Ge, Sn, and Pb are directly bonded; the elements are selected from those that are the same with each other and those that are different from each other; the film is disposed between two electrodes; and at least one of the electrodes is transparent. The laser luminescent element characterized in that: a thin film made from one of polymer and oligomer in which elements selected from Si, Ge, Sn, and Pb are directly bonded is disposed between two electrodes; and the elements are selected from those that are the same with each other and those that are different from each other.

Abstract: An EL element and a laser luminescent element are capable of emitting ultraviolet rays with high wavelength purity. The ultraviolet electroluminescent element includes a thin film made from one of a polymer and an oligomer in which the elements, selected from Si, Ge, Sn, and Pb, and directly bonded. The elements selected may be the same as or different from each other. The film is disposed between two electrodes. At least one of the electrodes is transparent. The laser luminescent element includes a thin film made from one of a polymer and an oligomer in which the elements selected from Si, Ge, Sn, and Pb, are directly bonded, and is disposed between two electrodes. The elements may be the same as or different from each other.

Abstract: A target is irradiated with a laser beam having an energy of h.nu./n, where n is an integer, instead of the photon energy h.nu. required for a reaction to proceed using a conventional single-photon excitation method. A desired reaction is selectively induced by the absorption of multiple photons instead of single photons. It is thus possible to induce a photoreaction in which an absorption is carried out in accordance with a selection theory different from that of single-photon absorption, and which is quite different from a photoreaction induced by a single-photon excitation. Namely, a target or reactant is irradiated with a photon energy h.nu..sub.2 having a wavelength integral times longer than that of the photon energy h.nu..sub.1 necessary for a photoreaction to proceed. Photon energy h.nu..sub.2 is either used in place of the photon energy h.nu..sub.1 necessary for a photoreaction, or together with the photon energy h.nu..sub.