A method of optimizing output signal of an optical receiver using Forward Error Correction (FEC), in which optical signals transmitted through an optical cable are converted into digital data of bits “1” and “0” on the basis of a reference voltage, and errors generated during transmission of the optical signals are corrected using the FEC, the method comprising:
- (a) extracting numbers of occurrence of errors for bits “1” and “0” recovered through the FEC;
- (b) comparing the extracted numbers of occurrence of errors for bits “1” and “0”;
- (c) controlling a reference voltage used to judge levels of the signals to be level “1” or “0” during the conversion of the optical signals into digital data if the numbers of occurrence of errors for bits “1” and “0” are not equal to each other as the result of the comparison;
- and
- (d) maintaining the reference voltage if the numbers of occurrence of errors for bits “1” and “0” are rendered equal to each other as the result of the comparison.