| 摘要 |
PURPOSE: To increase the luminescence efficiency of a planarized luminous element by forming a Fabry-Perot cavity which interposes a predetermined active layer between a lower reflector and an upper reflector. CONSTITUTION: A luminous element has a substrate 14, and a lower reflector 15, an active layer 16 and an upper reflector 17 that are sequentially formed on the substrate 14. The reflectors 15 and 17 form a Fabry-Perot cavity, interposing the layer 16 therebetween. The layer 16 is doped with a rare-earth element having an atomic number ranging from 57 to 71, and the rare-earth element is selected based on an optical transition that generates electroluminescence at a desired wavelength. A base mode of the cavity resonates with a wavelength of an excited radiation 13, and a main material of the layer 16 is selected from materials which cannot generate spontaneous luminescence. The thickness of the layer 16 is an integral multiple (1 to 5) ofλ/2, andλis obtained by, e.g. dividing the wavelength of the excited radiation 13 by a refractive index of the material of which the layer 16 is made.
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