Surface-emitting laser light source using two-dimensional photonic crystal

Abstract

The present invention intends to provide a surface-emitting laser light source using a two-dimensional photonic crystal in which the efficiency of extracting light in a direction perpendicular to the surface is high. In a laser light source provided with a two-dimensional photonic crystal layer created from a plate-shaped matrix body in which a large number of holes are periodically arranged and an active layer arranged on one side of the two-dimensional photonic crystal layer, the holes are created to be columnar with a predetermined cross-sectional shape such as a circular shape, and the main axis of each of the columnar holes is tilted to a surface of the matrix body. When provided with this two-dimensional photonic crystal layer, the surface-emitting laser source using a two-dimensional photonic crystal has a Q ⊥ value (i.e. a Q value in a direction perpendicular to the surface) of several thousands, which is suitable for an oscillation of laser light, and the efficiency of extracting light is high in the direction perpendicular to the surface.

1 . A surface-emitting laser light source using a two-dimensional photonic crystal, including an active layer and a two-dimensional photonic crystal provided on one side of the active layer,
 wherein:   the two-dimensional photonic crystal is created from a plate-shaped matrix body in which a large number of modified refractive index regions whose refractive index differs from that of the matrix body are periodically arranged, each of the regions has a columnar shape with a predetermined cross-sectional shape, and a main axis of each of the regions is tilted to a surface of the matrix body.   
     
     
         2 . The surface-emitting laser light source using a two-dimensional photonic crystal according to  claim 1 , wherein each of the modified refractive index regions has an obliquely standing columnar shape whose main axis is tilted to a line perpendicular to the matrix body at 20 to 45 degrees. 
     
     
         3 . The surface-emitting laser light source using a two-dimensional photonic crystal according to  claim 1 , wherein each of the modified refractive index regions has a shape of an obliquely standing equilateral triangle prism which is tilted to a base side of the equilateral triangle of a cross section on the matrix body as advancing from a plane opposite of the active layer towards the active layer. 
     
     
         4 . A surface-emitting laser light source using a two-dimensional photonic crystal, including an active layer and a two-dimensional photonic crystal provided on one side of the active layer,
 wherein:   the two-dimensional photonic crystal is created from a plate-shaped matrix body in which a large number of modified refractive index region groups made of a plurality of regions whose refractive index differs from that of the matrix body are periodically arranged, each of the region groups including at least two regions whose thicknesses differ from one another.   
     
     
         5 . The surface-emitting laser light source using a two-dimensional photonic crystal according to  claim 4 , wherein the modified refractive index regions within the modified refractive index region group have different plane shapes from one another. 
     
     
         6 . The surface-emitting laser light source using a two-dimensional photonic crystal according to  claim 5 , wherein each of the modified refractive index regions in the modified refractive index region group is thicker as an area of the plane shape thereof is larger. 
     
     
         7 . The surface-emitting laser light source using a two-dimensional photonic crystal according to  claim 6 , wherein the modified refractive index region group includes: a first modified refractive index region having a substantially rectangular plane shape; and a second modified refractive index region adjacent to a long side of the first modified refractive index region, having a substantially circular plane shape with a diameter shorter than the long side of the first modified refractive index region, having a smaller area and being thinner than the first modified refractive index region. 
     
     
         8 . The surface-emitting laser light source using a two-dimensional photonic crystal according to  claim 4 , wherein each of the regions of the modified refractive index region group is made of a hole. 
     
     
         9 . A method for manufacturing a surface-emitting laser light source using a two-dimensional photonic crystal, the light source including an active layer and a two-dimensional photonic crystal provided on one side of the active layer, and
 the method wherein the two-dimensional photonic crystal is manufactured by a process including:   creating a mask in which a large number of hole groups each including two or more holes with different areas are periodically arranged on a plate-shaped matrix body; and   dry etching the matrix body covered with the aforementioned mask and then discontinuing the dry etching before the holes created in the matrix body completely penetrate through the matrix body.   
     
     
         10 . The surface-emitting laser light source using a two-dimensional photonic crystal according to  claim 5 , wherein each of the regions of the modified refractive index region group is made of a hole. 
     
     
         11 . The surface-emitting laser light source using a two-dimensional photonic crystal according to  claim 6 , wherein each of the regions of the modified refractive index region group is made of a hole. 
     
     
         12 . The surface-emitting laser light source using a two-dimensional photonic crystal according to  claim 7 , wherein each of the regions of the modified refractive index region group is made of a hole.