| 摘要 |
PROBLEM TO BE SOLVED: To provide an LED element capable of suppressing a variation in an intensity distribution while maintaining an improvement in light extraction efficiency by a diffractive action.SOLUTION: In an LED element, an uneven region where a recessed part or a projecting part is periodically formed is arranged on a surface of an element and incident light into the uneven region is extracted to the outside of the element by using a diffractive action. In the LED element, the uneven region includes: a first uneven region where the period of the recessed part or the projecting part is longer than the optical wavelength of the incident light and shorter than the coherent length of the incident light; and a second uneven region where the period of the recessed part or the projecting part is longer than that of the recessed part or the projecting part in the first uneven region. |
