Semiconductor laser device

Abstract

A semiconductor laser according to the present invention comprises a λ/2 dielectric film (λ: in-medium wavelength of a dielectric film, for example, SiO 2 , Si 3 N 4 , Al 2 O 3 , and AlN) in contact with a facet of a resonator; and a first dielectric double layered film disposed on the dielectric film, which includes a first layer of a-Si and a second layer of a material having a refractive index lower than that of a-Si. The first layer has a thickness ¼ of an in-medium wavelength of a-Si, and the second layer has a thickness ¼ of a in-medium wavelength of the second layer. Therefore, it is possible to firmly stack the first dielectric double layered film and form a high reflectance film with high yield.

1 - 5 . (canceled) 
     
     
         6 . A semiconductor laser device comprising:
 a compound semiconductor laser body emitting light and having a resonator with facets mutually opposed to each other;   a dielectric film, selected from the group consisting of SiO 2 , Si 3 N 4 , Al 2 O 3 , and AlN, disposed on one of the facets of the resonator, and in contact with the facet of the resonator, wherein the dielectric film has a thickness 1/25 or less of a first in-medium wavelength, determined by a first refractive index, which is the refractive index of the material composing the dielectric film, and wavelength of the light emitted by the compound semiconductor laser body; and   a first dielectric double layered film on the dielectric film, having a first layer of amorphous silicon and a second layer of a material having a third refractive index, lower than a second refractive index, which is the refractive index of amorphous silicon, wherein
 the first layer is closer to the dielectric film than the second layer, and has a thickness exceeding ¼ of a second in-medium wavelength, determined by the second refractive index and the wavelength of the light emitted, and less than ½ of the second in-medium wavelength, and 
 the second layer has a thickness less than ¼ of a third in-medium wavelength, determined by the third refractive index and the wavelength of the light emitted. 
   
     
     
         7 . (canceled) 
     
     
         8 . A semiconductor laser device comprising:
 a compound semiconductor laser body emitting light and having a resonator with facets mutually opposed to each other;   a dielectric film, selected from the group consisting of SiO 2 , Si 3 N 4 , Al 2 O 3 , and AlN, disposed on one of the facets of the resonator, and in contact with the facet of the resonator, wherein the dielectric film has a thickness of 1/25 or less of a first in-medium wavelength, determined by a first refractive index, which is the refractive index of the material composing the dielectric film, and wavelength of the light emitted by the compound semiconductor laser body; and   a first dielectric double layered film on the dielectric film, having a first layer of amorphous silicon and a second layer of a material having a third refractive index, lower than a second refractive index, which is the refractive index of amorphous silicon, wherein
 the first layer is closer to the dielectric film than the second layer, and has a thickness less than ¼ of a second in-medium wavelength, determined by the second refractive index and the wavelength of the light emitted, and 
 the second layer has a thickness exceeding ¼ of a third in-medium wavelength, determined by the third refractive index and the wavelength of the light emitted, and less than ½ of the third in-medium wavelength. 
   
     
     
         9 . (canceled) 
     
     
         10 . The semiconductor laser device according to  claim 6 , further comprising at least one second dielectric double layered film disposed on the first dielectric double layered film, wherein
 the second dielectric double layered film has a first layer of amorphous silicon and a second layer of a material having a fourth refractive index, lower than the second refractive index,   the first layer is closer to the dielectric film than the second layer, and has a thickness ¼ of the second in-medium wavelength, determined by the second refractive index and the wavelength of the light emitted, and   the second layer has a thickness ¼ of a fourth in-medium wavelength, determined by the fourth refractive index and the wavelength of the light emitted.   
     
     
         11 . (canceled) 
     
     
         12 . The semiconductor laser device according to  claim 8 , further comprising at least one second dielectric double layered film disposed on the first dielectric double layered film, wherein
 the second dielectric double layered film has a first layer of amorphous silicon and a second layer of a material having a fourth refractive index, lower than the second refractive index,   the first layer is closer to the dielectric film than the second layer, and has a thickness ¼ of the second in-medium wavelength, determined by the second refractive index and the wavelength of the light emitted, and   the second layer has a thickness ¼ of a fourth in-medium wavelength, determined by the fourth refractive index and the wavelength of the light emitted.   
     
     
         13 . (canceled) 
     
     
         14 . The semiconductor laser device according to  claim 6 , further comprising at least one second dielectric double layered film disposed on the first dielectric double layered film, wherein
 the second dielectric double layered film has a first layer of amorphous silicon and a second layer of a material having a fourth refractive index, lower than the second refractive index,   the first layer is closer to the dielectric film than the second layer, and has a thickness exceeding ¼ of the second in-medium wavelength, determined by the second refractive index and the wavelength of the light emitted, and less than ½ of the second in-medium wavelength, and   the second layer has a thickness less than ¼ of a fourth in-medium wavelength, determined by the fourth refractive index and the wavelength of the light emitted.   
     
     
         15 . (canceled) 
     
     
         16 . The semiconductor laser device according to  claim 8 , further comprising at least one second dielectric double layered film disposed on the first dielectric double layered film, wherein
 the second dielectric double layered film has a first layer of amorphous silicon and a second layer of a material having a fourth refractive index, lower than the second refractive index,   the first layer is closer to the dielectric film than the second layer, and has a thickness exceeding ¼ of the second in-medium wavelength, determined by the second refractive index and the wavelength of the light emitted, and less than ½ of the second in-medium wavelength, and   the second layer has a thickness less than ¼ of a fourth in-medium wavelength, determined by the fourth refractive index and the wavelength of the light emitted.   
     
     
         17 . (canceled) 
     
     
         18 . The semiconductor laser device according to  claim 6 , further comprising at least one second dielectric double layered film disposed on the first dielectric double layered film, wherein
 the second dielectric double layered film has a first layer of amorphous silicon and a second layer of a material having a fourth refractive index, lower than the second refractive index,   the first layer is closer to the dielectric film than the second layer, and has a thickness less than ¼ of the second in-medium wavelength, determined by the second refractive index and the wavelength of the light emitted, and   the second layer has a thickness exceeding ¼ of a fourth in-medium wavelength, determined by the fourth refractive index and the wavelength of the light emitted, and less than ½ of the fourth in-medium wavelength.   
     
     
         19 . (canceled) 
     
     
         20 . The semiconductor laser device according to  claim 8 , further comprising at least one second dielectric double layered film disposed on the first dielectric double layered film, wherein
 the second dielectric double layered film has a first layer of amorphous silicon and a second layer of a material having a fourth refractive index, lower than the second refractive index,   the first layer is closer to the dielectric film than the second layer, and has a thickness less than ¼ of the second in-medium wavelength, determined by the second refractive index and the wavelength of the light emitted, and   the second layer has a thickness exceeding ¼ of a fourth in-medium wavelength, determined by the fourth refractive index and the wavelength of the light emitted, and less than ½ of the fourth in-medium wavelength.