| 摘要 |
PURPOSE:To obtain a semiconductor laser having a narrow spectral beam width by partly varying the period of a diffraction grating so that the optical intensity distribution in the resonator direction becomes flat. CONSTITUTION:The periods of diffraction gratings 2 to be associated therein are so partly varied that there are two or more regions of different periods of vibration and two or more regions of the same period, the intensity of coupling the light to the gratings 2 is controlled to flatten the intensity distribution of the light in the resonator direction. That is, the grating 2 is formed on the surface of a n-type InP substrate 1, the periods are uniform in the regions 1-7 of the grating 2, the periods of the grating of regions 1, 3, 5, 7 are equal, the periods of the grating of the regions 2, 4, 6 are equal, and the regions 2, 4, 6 are operated as phase regulating region. Thus, a semiconductor laser having a fine spectral beam width can be obtained. |
