Surface emitting laser array and production method therefor
A surface emitting laser array having a plurality of surface emitting lasers arranged in an array, each of the surface emitting lasers being provided with a two-dimensional photonic crystal having a resonance mode in an in-plane direction and with an active layer. The surface emitting laser has a mesa-shaped inclined side wall surface. When a maximum light-receiving angle with respect to the mesa-shaped inclined side wall surface at which an incident light is coupled with a waveguide containing the two-dimensional photonic crystal is denoted as θmax°, an angle formed by a plane of the two-dimensional photonic crystal and the mesa-shaped inclined side wall surface is controlled so as to exceed (90+θmax)° or be smaller than (90−θmax)°.
1. A surface emitting laser array comprising a plurality of surface emitting lasers arranged in an array, each of the surface emitting lasers being provided with a two-dimensional photonic crystal having a resonance mode in an in-plane direction and with an active layer,
wherein the surface emitting laser has a mesa-shaped inclined side wall surface,
wherein when a maximum light-receiving angle with respect to the mesa-shaped inclined side wall surface at which an incident light is coupled with a waveguide containing the two-dimensional photonic crystal is denoted as θmax°, an angle formed by a plane of the two-dimensional photonic crystal and the mesa-shaped inclined side wall surface is controlled so as to exceed (90+θmax)° or be smaller than (90−θmax)° and
wherein the mesa-shaped inclined side wall surface is formed of a curved surface having the angle exceeding (90+θmax)° or smaller than (90−θmax)°.
2. The surface emitting laser array according to claim 1 , wherein the two-dimensional photonic crystal is constituted by a semiconductor layer.
3. The surface emitting laser array according to claim 2 , wherein the semiconductor layer is of a nitride semiconductor.
4. A method for producing a surface emitting laser array comprising a plurality of arranged surface emitting lasers each provided with a two-dimensional photonic crystal having a resonance mode in an in-plane direction and with an active layer, the method comprising the steps of:
forming a mask for selective growth having an opening aperture on a substrate;
forming a semiconductor layer provided with a mesa-shaped inclined side wall surface by selective growth starting from the aperture; and
forming the two-dimensional photonic crystal in the semiconductor layer,
wherein, in the step of forming the semiconductor layer, when a maximum light-receiving angle with respect to the inclined side wall surface at which an incident light couples with a waveguide containing the two-dimensional photonic crystal is denoted as θmax°, the semiconductor layer is formed so that an angle formed by a plane of the two-dimensional photonic crystal and the mesa-shaped inclined side wall surface exceeds (90+θmax)° or is smaller than (90−θmax)°, and
wherein the mesa-shaped inclined side wall surface is formed of a curved surface having the angle exceeding (90+θmax)° or smaller than (90−θmax)°.
5. The method according to claim 4 , wherein the semiconductor layer is of a nitride semiconductor.