The present semiconductor light emitting element is a semiconductor light emitting element including an active layer, an upper cladding layer and a lower cladding layer that sandwich the active layer, and a phase modulation layer optically coupled to the active layer, in which the phase modulation layer includes a basic layer and a plurality of different refractive index regions that are different in refractive index from the basic layer, and the plurality of different refractive index regions are disposed so as to form a pattern in a region outside a light line on a reciprocal lattice space in the phase modulation layer.