| 摘要 |
PROBLEM TO BE SOLVED: To provide a broad band adjustable laser, which generates optical output signal corresponding such as to the wavelength of a wavelength division multiplexing (WDM) system, N-pieces of channels, with any one of the N-pieces of different axial modes. SOLUTION: An adjustable semiconductor laser has a gain region 12 having an MGW active region 12.1, grating DFB regions 12.2 of a uniform pitch and a first waveguide 12.3. A cavity resonance is formed of a composite reflecting region 14, which has a second MQW region 14.1 and a second waveguide 14.3, and the regions 12.2. Due to the voltage applied to this region 14, a quantum confining Stark effect is caused and as a result, the wavelength of the laser is changed. |
