| 摘要 |
<p>A semiconductor optical device for focusing an optical beam comprises a substrate (11) doped to a first conduction type, a semiconductor layer (13) doped to a conduction type different from that of the substrate, a recombination region (12) formed between the substrate and the second semiconductor layer, a first electrode (14) provided on a bottom surface of the substrate, and a second electrode (15) provided on a top surface of the second semiconductor layer, wherein the first electrode means is transparent to the optical beam and passing the optical beam freely therethrough, said second electrode means is provided with a passage of the optical beam with a size at least exceeding the carrier diffusion length in the semiconductor layer, so that there appears a profile of refractive index in the recombination region such that the refractive index assumes a minimum refraction index in correspondence to a center of the circular passage and a maximum refraction index in correspondence to an edge of the passage.</p> |
