| 摘要 |
PURPOSE: To simplify the structure and to improve the sensitivity by constituting a semiconductor structure having an activated layer, distributed feedback, and a λ/4 phase shifter. CONSTITUTION: Layers of a distributed feedback(DFB) semiconductor structure 10 consisting of accumulated layers include an activated layer 12 which receives a light beam 14 with a frequency Fi . This structure has a diffraction grating 16 which is optically coupled to the activated layer 12, and this grating has a center area 18 where optical phase shift occurs. A device which takes out a voltage at a terminal of this structure consists of a center electrode 30 placed above the center area 18 of the grating where optical phase shift occurs. Two electrodes 22 and 24 are arranged on both sides of the center electrode and are electrically insulated. All electrode 25 is arranged under this structure and is connected to, for example, the earth or the ground, and the electrode 30 for taking-out is connected to a resistance 32 and a heterodyne detection circuit 36. |
