| 摘要 |
PURPOSE:To make possible low noise operation of a wide wavelength region by selectively removing part of N layer to expose P layer and letting long wavelength light enter the N layer remained on the surface and short wavelength light the exposed P layer respectively. CONSTITUTION:The N layer of the portion of a region 5 is removed to expose P layer. The long wavelength light having entered the region which has the N layer on the surface arrives at the P layer while being hardly absorbed in the N layer and itturns out that injection of electrons is accomplished there. In this case, the hole injection in the N layer is small and therefore the production of noise is kept low. On the other hand, the short wavelength light is radiated to the region 5 and electrons are injected near the surface thereof to allow avalanche current to be produced and therefore no adverse influence is given by the hole injection. |
