| 摘要 |
<p>PURPOSE: To increase electric bandwidth by supplying a bias current which is larger than the induced emission threshold bias current of a semiconductor diode and impressing an input signal, which has wavelength that the wavelength of the minimum reflection factor of a reflection preventive film, is close to an optical cavity. CONSTITUTION: An optical amplifier has an active region 10, a lower coating layer 12, an upper coating layer 14, a substrate 16, and a cap layer 18. The active region 10 is formed of InGaAsP, the lower coating layer 12 is formed of an n-InP, and the upper coating layer 14 is formed of a p-InP, and the substrate 16 is formed of an n-InP and the cap layer 18 is formed of a p-InGaAsP. The bias current is 1 to 4 times as large as the threshold bias current. An input light signal has wavelength that the wavelength of the minimum reflection factor of antireflecting films 36 and 38 is close to. The optional amplifier which is operated indicates a wide electric bandwidth of 1 to 10GHz.</p> |
