| 摘要 |
PROBLEM TO BE SOLVED: To provide gain characteristic which is independent of polarization and to improve a saturation input light intensity level and saturation gain characteristics. SOLUTION: This semiconductor optical amplifier is provided with an optical waveguide structure composed of a multi-mode waveguide region 1, which is a 1×1 multi-mode interference type (1×1-MMI) optical waveguide and a pair of single-mode waveguide regions 2 and 3 connected to both the end parts. For the multi-mode waveguide region 1, a length is about 340μm and a waveguide width W1 is 12μm. For the single-mode waveguide regions 2 and 3, the length is about 20μm and the waveguide width W2 is 1μm respectively. By using the 1×1-MMI optical waveguide, the gain characteristic independent of the polarization are obtained, and the saturation input light intensity level and the saturation gain characteristics are improved. |
