Semiconductor light emitting element

A semiconductor light emitting element, comprising;

• a semiconductor stack part that includes a light emitting layer;
• a diffractive face that light emitted from the light emitting layer is incident to;
• convex portions or concave portions formed in a period which is longer than an optical wavelength of the light and is shorter than a coherent length of the light, wherein the diffractive face reflects incident light in multimode according to Bragg's condition of diffraction and transmits the incident light in multimode according to the Bragg's condition of diffraction;
• and
• a reflective face which reflects multimode light diffracted at the diffractive face and let the multimode light be incident to the diffractive face again,
• wherein the semiconductor stack part is formed on the diffractive face, and
• wherein the convex portions or the concave portions include a side surface and a curved portion which curves and extends to a center side of the convex portions or the concave portions from an upper end of the side surface.