| 摘要 |
PURPOSE:To stably form a grating by a method wherein a multiple-quantum-well structure of a light guide layer is made partially disordered by an ion implantation operation and an annealing operation using a a focused ion beam. CONSTITUTION:For example, Si is implanted into a multiple-quantum-well light guide layer 3 in a prescribed width at equal intervals by using a focused ion beam method. After that, an annealing treatment is executed, e.g., at 800 deg.C for 30 minutes under atmospheric pressure. Then, a multiple-quantum-well structure is destroyed; a region into which Si has been implanted in the guide layer 3 becomes a disordered region 5. A refractive index of the region 5 is different from that of an obliquely disordered region; accordingly, a distribution of the refractive index in the longitudinal direction, i.e. a grating, is formed on the guide layer 3. By this setup, the grating can be formed stably. |
