| 摘要 |
PROBLEM TO BE SOLVED: To improve optical output by optimizing the refractive index of the layer stacked on a light emitting layer thereby reducing the interface reflection loss. SOLUTION: The refractive index to the wavelength of the emitted light in the clad layer stacked on a light emitting layer decreases continuously from the lower part to the upper part of the clad layer 7. And, a silicon nitride film 8 is stacked on the clad layer 7, and a polyimide film 8 is stacked on the silicon nitride film 8, and epoxy resin 12 is made on the polyimide film 9. At this time, the refractive index is set to n1 >n2 >n3 >n4 defining that the refractive index to the wavelength of the emitted light at the upper part of the clad layer 7 is n1 , that the refractive index to the wavelength of the emitted light of the silicon nitride film 8 is n2 , that the refractive index to the wavelength of the emitted light of the polyimide film 9 is n3 , and that the refractive index to the wavelength of the emitted light of the epoxy resin 12 is n4 . |
