Semiconductor light emitting element

A semiconductor light emitting element comprising:

• an active layer;
• a pair of cladding layers between which the active layer is interposed;
• and
• a phase modulation layer optically coupled to the active layer,
• wherein the phase modulation layer comprises:
• a base layer;
• and
• a plurality of different refractive index regions having different refractive indices from the base layer,
• wherein when an XYZ orthogonal coordinate system having a thickness direction of the phase modulation layer as a Z-axis direction is set and a square lattice of a virtual lattice constant is set in an XY plane,
• wherein each of the different refractive index regions is disposed so that a centroid position thereof is shifted from a lattice point position in the virtual square lattice by a distance r,
• wherein in the phase modulation layer, all the different refractive index regions have, in the XY plane, same distance r,
• wherein a shape of each of the different refractive index regions in the XY plane is a square, a regular hexagon, a regular octagon, or a regular hexadecagon.