| 摘要 |
PROBLEM TO BE SOLVED: To sufficiently increase the inter-subband absorption in a multiple quantum well structure and to stabilize and ensure the operation as an optical switch. SOLUTION: The semiconductor optical switch has a GaN waveguide having a multiple quantum well structure of a nitride semiconductor which absorbs light in a near IR region by the inter-subband transition. The waveguide is obtained by successively laminating a 2 μm-thick GaN layer 32, first multiple quantum well structure 33 having 50 quantum wells, 0.7 μm-thick GaN layer 34, second multiple quantum well structure 35 having 50 quantum wells, 0.7 μm-thick GaN layer 36, third multiple quantum well structure 37 having 50 wells, and 2 μm-thick GaN layer 38 on a sapphire substrate 31. |
