| 摘要 |
<p>A first interferometer (20) comprises a first delay element (21) and a first phase shift element (22), and a second interferometer (30) comprises a second delay element (31) and a second phase shift element (32). The amounts of phase shift in the first and second phase shift element are zero and À/2, respectively. A first photo detector (40) comprises first and second photodiodes (41, 42) connected in parallel, and a second photo detector (50) comprises third and fourth photodiodes (51, 52) connected in series. The first photodiode (41) is provided with a first optical output of the first interferometer (20), the second photodiode (42) is provided with a first optical output of the second interferometer (30), the third photodiode (51) is provided with a second optical output of the first interferometer (20), and the fourth photodiode (52) is provided with a second optical output of the second interferometer (30) . A signal process circuit (60) recovers transmitted data based on output signals of the first and second photo detectors (40, 50).</p> |
