| 摘要 |
PURPOSE:To improve photodetection efficiency and improve response characteristics by providing a photodetecting window with a dome shape. CONSTITUTION:A light 8 applied to a photodetector enters through a photodetecting window 7. Because of the dome shape of the window 7, the light 8 is refracted at the window 5 and condensed toward the center part of a P-N junction 3. The light which reaches the P-N junction 3 is absorbed by a depletion layer which is spread in the junction 3 and electron-hole pairs are produced. The pairs are drifted by an electric field induced by a reverse bias voltage applied to the P-N junction beforehand and are taken out as a photocurrent. At that time, as the light is condensed by the dome-shaped photodetecting window, the light corresponding to the area larger than the area of the P-N junction can be introduced into the P-N junction so that photodetection efficiency can be improved. |
