| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical receiver in which erroneous detection of recovery of an optical signal from a signal interruption state is prevented. <P>SOLUTION: An optical receiver 1 of the present invention comprises a light receiving element 2 for converting an input optical signal O<SB>in</SB>into a current, a preamplifier 3 for converting the current into a voltage signal and outputting it, and an LOS detection circuit for detecting reduction of a level of the input optical signal O<SB>in</SB>based on the output signal from the preamplifier 3, wherein the LOS detection circuit 6 includes a bottom hold circuit 11a for holding a minimal value of the output signal of the preamplifier 3, and a comparator 12a for setting an output W<SB>a</SB>if an output signal V<SB>B</SB>of the bottom hold circuit 11a is greater than a threshold voltage V<SB>th(-)</SB>. <P>COPYRIGHT: (C)2007,JPO&INPIT |
