Two-dimensional photonic crystal surface-emitting laser

A two-dimensional photonic crystal surface emitting laser comprising a laminated structure including:

• an active layer for generating light having a wavelength λL by receiving an injection of an electric current;
• and
• a two-dimensional photonic crystal layer in which refractive index distribution is formed by modified refractive index regions two-dimensionally arranged in a plate-shaped base member, where a refractive index of the modified refractive index regions differs from that of the base member,
• the two-dimensional photonic crystal surface emitting laser emitting a laser beam in a direction of an inclination angle θ from a normal to the two-dimensional photonic crystal layer, wherein
• the modified refractive index regions in the two-dimensional photonic crystal layer 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 λL is created by forming a two-dimensional standing wave while the light having the wavelength λL is prevented from being emitted to an outside, and
• a modulation phase Ψ at each lattice point is expressed as Ψ=r↑·G′↑ by using a position vector r↑ of each lattice point and a reciprocal lattice vector G′↑, (g′x, g′y)=(kx±|k↑|(sin θ cos φ)/neff, ky±|k↑|(sin θ sin φ)/neff), the reciprocal lattice vector G′↑ being expressed by using:
• a wave vector k↑=(kx, ky) of the light having the wavelength λL in the two-dimensional photonic crystal layer;
• an effective refractive index neff of the two-dimensional photonic crystal layer;
• and an azimuthal angle φ from a predetermined reference line of the basic two-dimensional lattice.