| 摘要 |
PURPOSE:To obtain the channel switch with a small transmission loss by a method wherein a P-N-P-N element of the structure having a small backward light leakage current is used. CONSTITUTION:In a lateral type P-N-P-N element, an anode terminal A is connected to a combined electrode and light shielding substance 20, and the beam of a light-emitting diode 14 is shut out by having the electrode area larger than a P type diffusion region and the entire area of the depletion region J1S opposing to the light-emitting diode 14 is covered by the electrode. Also, by having the optimized electrode design, the leakage current can be reduced by 70%, and the communication loss in the case where a bridge-connection type channel switch is used can be reduced to 0.1dB or below. In addition, the effect on the driving current of the light irradiated to a depletion layer J2S is removed by providing a combined electrode and light-shielding substance 20, and the P-N-P-N element of small backward light leakage current can be obtained. |
