| 摘要 |
PURPOSE:To secure a broad band by employing 1st and 2nd light receiving elements manufactured by the same process. CONSTITUTION:A cathode of a 2nd light receiving element 11 such as a diode manufactured by the same process as a 1st light receiving element 5 is connected between a voltage division circuit 8 and an input terminal 2 and its anode is connected to the input terminal 2, and a DC potential at an AC connecting point 7 is set so that an average voltage at a voltage division point 9 is a potential of a cathode 12 of an element 5 and a current flowing through a junction capacitance of the element 5 is cancelled by the element 11 and the circuit 8. The 2nd required light receiving element is employed in place of a capacitor, then the optical reception circuit ensuring a sufficient band is obtained even when an impurity concentration or the like is in dispersion. |
