Nitride-based semiconductor laser device

Abstract

A nitride-based semiconductor laser device capable of elongating the life thereof is obtained. This nitride-based semiconductor laser device comprises a first cladding layer consisting of a first conductivity type nitride-based semiconductor, an emission layer, formed on the first cladding layer, consisting of a nitride-based semiconductor and a second cladding layer, formed on the emission layer, consisting of a second conductivity type nitride-based semiconductor, while the emission layer includes an active layer emitting light, a light guiding layer for confining light and a carrier blocking layer, arranged between the active layer and the light guiding layer, having a larger band gap than the light guiding layer.

1 - 24 . (canceled) 
     
     
         25 . A nitride-based semiconductor laser device comprising:
 a) a first cladding layer made of a first conductivity type nitride-based semiconductor;   b) a second cladding layer made of a second conductivity type nitride-based semiconductor; and   c) an emission layer, formed between said first cladding layer and said second cladding layer, made of a nitride-based semiconductor, wherein said emission layer includes:
 an active layer; and 
 a light guiding layer for confining light formed adjacent to at least a surface of a side of said active layer on which said first cladding layer is formed; 
   d) a first light spreading layer having a smaller refractive index and a larger band gap than said first cladding layer, arranged between said light guiding layer adjacent to said active layer and said first cladding layer; and   e) a second light spreading layer having a smaller refractive index and a larger band gap than said second cladding layer, arranged between said active layer and said second cladding layer.   
     
     
         26 . A nitride-based semiconductor laser device comprising:
 a) a first cladding layer made of a first conductivity type nitride-based semiconductor;   b) a second cladding layer made of a second conductivity type nitride-based semiconductor; and   c) an emission layer, formed between said first cladding layer and said second cladding layer, made of a nitride-based semiconductor, wherein said emission layer includes:
 an active layer; and 
 a light guiding layer for confining light formed adjacent to at least a surface of a side of said active layer on which said first cladding layer is formed; 
   d) a first nitride-based semiconductor layer having a smaller refractive index and a larger band gap than said first cladding layer, arranged between said light guiding layer adjacent to said active layer and said first cladding layer; and   e) a second nitride-based semiconductor layer having a smaller refractive index and a larger band gap than said second cladding layer, arranged between said active layer and said second cladding layer.   
     
     
         27 . A nitride-based semiconductor laser device according to  claim 25 , wherein
 said nitride-based semiconductor laser device reduces the degree of optical confinement in said emission layer, thereby reducing a vertical beam divergence angle to not more than 20°.   
     
     
         28 . A nitride-based semiconductor laser device according to  claim 26 , wherein
 said nitride-based semiconductor laser device reduces the degree of optical confinement in said emission layer, thereby reducing a vertical beam divergence angle to not more than 20°.