Surface emitting laser, information obtaining apparatus, and imaging apparatus

A wavelength-tunable surface emitting laser comprising:

• a first reflector;
• an active layer disposed on the first reflector;
• a beam portion disposed over the active layer with an air gap therebetween;
• and
• a second reflector disposed on the beam portion,
• wherein the second reflector has a distributed Bragg reflector consisting of a stack of dielectric layers,
• wherein the beam portion has a plurality of reflecting surfaces therein, and
• wherein the beam portion is configured to causes a part of light emitted from the active layer to be reflected by a reflecting surface at the interface between the beam portion and the air gap, a reflecting surface at the interface between the beam portion and the second reflector, and the plurality of reflecting surfaces in the beam portion, and to cause light rays reflected by the reflecting surfaces of the beam portion to interfere with each other so as to weaken the interference effect due to the reflecting surface at the interface between the beam portion and the air gap and the reflecting surface at the interface between the beam portion and the second reflector.

A wavelength-tunable surface emitting laser comprising:

• a first reflector;
• an active layer disposed on the first reflector;
• a beam portion disposed over the active layer with an air gap therebetween;
• and
• a second reflector disposed on the beam portion,
• wherein the second reflector has a distributed Bragg reflector consisting of a stack of dielectric layers, and
• wherein the beam portion is formed of a multilayer film such that a wavelength band having a reflectance of 99.5% or more in the reflectance spectrum of the second reflector is wider than that in the case where the beam portion is formed of a single layer.