| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an optical semiconductor device which assures large extinction ratio and stable oscillation spectrum and moreover enables optical transmission in the small bit error rate. SOLUTION: A gain coupling DFB laser including a mechanism to periodically modulate a gain in the resonator direction, namely diffraction grating G1, and an optical modulator including a mechanism to apply an inverse bias field to a waveguide layer 23A including the diffraction grating G2, namely electrode 28 are integrated face to face on the same substrate 21.</p> |
