| 摘要 |
<p>A multilevel light intensity modulator divides input light into n (n is an integer of 2 or above) light beams being sent to n branch waveguides. An MZI optical modulation section is provided on each branch waveguide, and each MZI optical modulation section divides the input light with a branch ratio different from 0.5:0.5, and outputs a binary optical signal having a deteriorated extinction ratio by being turned on/off by a binary electrical signal. Output light beams from respective MZI optical modulation sections are multiplexed and an optical signal subjected to light intensity modulation of 2<SUP>n </SUP>level not including zero level isoutputted. Consequently, light intensity modulation of four-level or above not including zero level can be achieved through a practical arrangement employing a binary electrical signal.</p> |
