Surface emitting laser element, surface emitting laser array, optical scanner and imaging apparatus

PROBLEM TO BE SOLVED: To achieve a stable polarization state without increasing the cost nor causing the degradation of a beam shape.SOLUTION: A surface emitting laser element comprises: a substrate having a principal plane of which the normal direction inclines, by 15 degrees, toward a crystal orientation [1 1 1] direction with respect to a crystal orientation [1 0 0] direction; and a laminate stacked on the substrate. The surface emitting laser element has a strain field owing to oxidation at least partially in the vicinity of an oxide layer 108a of an oxidation constriction structure included in the laminate. The strain field changes in strain between X axial direction and Y axial direction. In this case, an optical property of a quantum well in an active layer results from addition of an optical anisotropy of the substrate and an optical anisotropy according to the strain field in the vicinity of the oxide layer 108a. Therefore, it becomes possible to achieve a stable polarization state without increasing the cost nor causing the degradation of a beam shape.SELECTED DRAWING: Figure 7