Light-emitting device

A light-emitting device, comprising:

• a surface emitting laser element including a first light output surface and a second light output surface opposing each other;
• a light guide layer disposed on the second light output surface;
• and
• a reflective metasurface disposed on the second light output surface via the light guide layer, wherein
• the reflective metasurface includes
• a light transmissive layer disposed on an opposite side of the second light output surface with respect to the light guide layer, the light transmissive layer including a dielectric layer, the light transmissive layer including a first surface located between the light guide layer and the dielectric layer, and a second surface located on an opposite side of the first surface with respect to the dielectric layer,
• a first metal film disposed on the first surface, and
• a second metal film disposed on the second surface, the second metal film reflecting, towards the light guide layer, a laser light inputted from the surface emitting laser element to the light transmissive layer via the light guide layer,
• a plurality of unit regions are set on the first surface of the light transmissive layer so as to constitute a one-dimensional array or a two-dimensional array, each of the plurality of unit regions includes an exposed portion of the light transmissive layer which faces the light guide layer without being blocked by the first metal film, and a width of each of the plurality of unit regions and a thickness of the light transmissive layer are shorter than a wavelength of the laser light,
• the reflective metasurface is configured to modulate a phase of the laser light for each of the unit regions, and
• the laser light that is modulated by the reflective metasurface passes through the second light output surface, and then, is outputted from the first light output surface.