Light emitting element, light source device, display device, head-mounted display, and biological information acquisition apparatus

A light emitting element, comprising:

• an active layer configured to generate light;
• and
• a first reflecting mirror over the active layer, the first reflecting mirror including:
• a multilayer-film reflecting mirror having a first surface and a second surface opposite to the first surface and closer to the active layer than the first surface, the multilayer-film reflecting mirror including:
• a first refractive-index layer having a first refractive index;
• and
• a second refractive-index layer having a second refractive index higher than the first refractive index, the first refractive-index layer and the second refractive-index layer alternately stacked;
• and
• a first layer on the first surface of the multilayer-film reflecting mirror,
• wherein:
• the first surface has an emission region from which the light generated in the active layer is emitted,
• the first layer is in the emission region of the first surface and is configured to absorb a portion of the light emitted from the first surface and transmit another portion of the light through the first layer, and
• the first layer has a thickness having a transmissivity ratio I1/I0 of more than 0 and 0.1 or less,
• where I0 is a transmissivity of the light generated in the active layer transmitted from the multilayer-film reflecting mirror to air assumed to be on the multilayer-film reflecting mirror, and
• I1 is a transmissivity of the light generated in the active layer transmitted from the multilayer-film reflecting mirror on which the first layer is formed to the air.

A light emitting element, comprising:

• an active layer configured to generate light;
• and
• a first reflecting mirror over the active layer, the first reflecting mirror including:
• a multilayer-film reflecting mirror having a first surface and a second surface opposite to the first surface and closer to the active layer than the first surface, the multilayer-film reflecting mirror including:
• a first refractive-index layer having a first refractive index;
• and
• a second refractive-index layer having a second refractive index higher than the first refractive index, the first refractive-index layer and the second refractive-index layer alternately stacked;
• and
• a first layer on the first surface of the multilayer-film reflecting mirror,
• wherein:
• the first surface has an emission region from which the light generated in the active layer is emitted,
• the first layer is in the emission region of the first surface and is configured to absorb a portion of the light emitted from the first surface and transmit another portion of the light through the first layer, and
• an optical output of the light emitting element is 0.01 μW or more and 100 μW or less.