| 摘要 |
<p>PROBLEM TO BE SOLVED: To realize a basic lateral mode up to a high output and to realize a diffracted limit light up to a high output in a light emitting device. SOLUTION: A second clad layer having a refractive index smaller than that of a core is formed between the core and a first clad layer, and an optical waveguide element 51 is manufactured by forming a parallel optical waveguide 47 wherein a diffraction grating 52 is provided in the light incident end surface side of the second clad layer, a tapered optical waveguide 48 connected to it and a parallel optical waveguide 49 connected to it. The light exiting side of a semiconductor laser 29 which oscillates the basic lateral mode up to high output is directly coupled to the end surface side having the parallel waveguide wherein the diffraction grating 52 of the optical waveguide element 51 is formed so that the distribution of light intensity of the semiconductor laser nearly coincides with a propagating mode of the optical waveguide element. Further, the light exiting side end surface side of the optical waveguide element 51 is directly coupled to the light incident side end surface of a semiconductor optical amplifier 39 so that the propagating mode of the optical waveguide element 51 nearly coincides with the distribution of light intensity of the semiconductor optical amplifier 39.</p> |
