Surface emitting laser element, surface emitting laser array, optical scanning device, and image forming apparatus

An optical scanning device which scans a surface to be scanned by a laser beam, comprising:

• a light source which includes a surface emitting laser element configured to emit a laser beam in a direction perpendicular to a surface of a substrate of the surface emitting laser element, a normal direction of a principal surface of the substrate being inclined to one direction of a [1 1 1] crystal orientation relative to one direction of a [1 0 0] crystal orientation, the surface emitting laser element including
• a resonator structural body including an active layer,
• first and second semiconductor distributed Bragg reflectors which sandwich the resonator structural body and include a confinement structure in which a current passing through region is surrounded by an oxidized layer formed by oxidizing a part of a layer to be selectively oxidized containing at least aluminum, and
• a plurality of semiconductor layers stacked on the substrate;
• a deflecting unit which deflects the laser beam from the light source;
• and
• a scanning optical system which condenses the laser beam deflected by the deflecting unit onto the surface to be scanned,
• wherein in the confinement structure in which the current passing through region is surrounded by the oxidized layer
• a shape of the current passing through region is symmetrical to a first axis which is orthogonal to one direction of the [1 0 0] crystal orientation and one direction of the [1 1 1] crystal orientation, is parallel to the surface of the substrate, and passes through a center of the current passing through region;
• and is symmetrical to a second axis which is orthogonal to the normal direction and the first axis and passes through the center of the current passing through region,
• a length of the current passing through region in the first axis direction is different from a length in the second axis direction,
• a thickness of the oxidized layer surrounding the current passing through region is different between in a direction parallel to the second axis direction and in a direction parallel to the first axis direction, and
• a radiation angle of the laser beam in the first axis direction is the same as a radiation angle of the laser beam in the second axis direction.