| 摘要 |
<p>A guided-wave optical branching component composed of Mach-Zehnder interferometer having two or more directional couplers (34, 35, 43, 44, 50, 51, 52, 75, 76, 85, 86). A slight difference DELTA L in the optical-path length is given to the two or more optical waveguides (32, 33, 41, 42, 82, 83, 84) connecting the two or more directional couplers (34, 35, 43, 44, 50, 51, 52, 75, 76, 85, 86). The difference of the optical-path length is determined less than the shortest wavelength in the operational wavelength region of the guided-wave optical branching component, and a coupling ratio of each of the two directional couplers (34, 35, 43, 44, 50, 51, 52, 75, 76, 85, 86) is determined to monotonically increase according to the wavelength in the operational wavelength region. By using the optical branching components thus constructed (i.e., Mach-Zehnder interferometer type 3-dB optical coupler (101,102)) in conjunction with a phase shifter, Mach-Zehnder interferometer type optical switch can be achieved.</p> |
