Abstract:
The present invention provides a two-dimensional photonic crystal surface emitting laser that can emit an inclined beam at a larger inclination angle with a smaller loss in light. Provided is a two-dimensional photonic crystal surface emitting laser comprising a laminated structure including: a two-dimensional photonic crystal (2DPC) layer 11 in which refractive index distribution is formed by two-dimensionally arranging air holes 111 in a plate-shaped base member 114; and an active layer 12 for generating light having a wavelength » L by receiving an injection of an electric current, the two-dimensional photonic crystal surface emitting laser emitting a laser beam in the direction of an inclination angle ¸ from the normal to the 2DPC layer 11, wherein the air holes 111 in the 2DPC layer 11 are modulated at respective lattice points of a basic two-dimensional lattice whose periodicity is determined such that a resonant state of the light having the wavelength » L is created by forming a two-dimensional standing wave while the light is prevented from being emitted to the outside, and a phase ¨ of the modulation is expressed as ¨=r†‘·G'†‘ by using a position vector r†‘ of each lattice point and a reciprocal lattice vector G'†‘=(g' x , g' y )=(k x ±|k†‘|(sin¸ cosÕ)/n eff , k y ±|k†‘|(sin¸ sinÕ)/n eff ), the reciprocal lattice vector G'†‘ being expressed by using: a wave vector k†‘=(k x , k y ) of the light having the wavelength » L in the 2DPC layer 11; an effective refractive index n eff of the 2DPC layer 11; and an azimuthal angle Õ from a predetermined reference line of the basic two-dimensional lattice.