| 摘要 |
PURPOSE:To prevent the malfunction due to noises by a method wherein a photo receiving element is shielded with a conductive layer. CONSTITUTION:A shielding conductive layer 38 is formed on the inner surface of one of apertures 33 and 34 bored in a ceramic substrate 31, and a ceramic substrate 32 is fixed on the back of the substrate 31. The photo receiving elements 30 are fixed at the positions corresponding to the apertures 33 and 34 in the upper part of the substrate 32. The shielding conductive layer 39 is formed so as to cover the front of the substrate 32, and the shielding conductive layer 40 is formed so as to cover the back. During operation, an emitted light is radiated from a photo transmitting window 36 and then transferred through an optical fiber. The transmitted light from the other optical fiber comes in from a photo transmitting window 37 and is then supplied to the element 30. |
