| 摘要 |
PURPOSE: An optical isolator using multi mode interference in quasi state is provided to improve optical integration and to reduce performance degradation due to phase error between waveguide modes. CONSTITUTION: The optical isolator using a quasi state multi mode interference comprises an input waveguide(1), a multi mode interferometer(2) and two output waveguides(3,4). The multi mode interferometer uses a multi mode interference state in quasi state having a short imaging length. The width of the input waveguide is 1/3 of the width the multi mode interferometer, and thus excitation coefficients as to four low order modes in the multi mode interferometer are distributed symmetrically and thus extinction ratio characteristics of the quasi state is improved.
|
