A light emitting device includes a substrate supporting a first light emitting element and a second light emitting element, the first light emitting element being configured to emit, in a first principal direction, light in a first wavelength band and the second light emitting element being configured to emit, in the first principal direction, light in a second wavelength band different from the first wavelength band, each light emitting element including: a light emitting diode layer, extending in a plane perpendicular to the first direction, having a thickness of 10 microns or less in the first direction and a maximum lateral dimension of 100 microns or less orthogonal to the first direction, the light emitting diode layer including a semiconductor material; and one or more layers configured to enhance an optical mode of the light emitted in the corresponding first or second wavelength band perpendicular to the plane and/or suppress an optical mode of the light emitted in the corresponding first or second wavelength band in the plane.