| 摘要 |
PROBLEM TO BE SOLVED: To suppress crosstalk between channels in the case of separating the optical energy of different wavelengths into the separate channels by cascade connecting plural wavelength routers and using space filtering. SOLUTION: A specified waveguide in the input of a first wavelength router 302 functions as a point source A0 and a corresponding primary image B0 is formed inside intervals P1 and P2 corresponding to the center zone of the first wavelength router 302 by the first wavelength router 302. Other than the primary image, secondary images B1 and B2 are formed by the grating lobe of the first wavelength router 302. An unrequired image is generated inside the center zone of a second wavelength router 304 and thus, the unrequired image is generated on the output side of the free space 308 of a position at which an output waveguide 310 is in contact with the free space 308. The space filtering for preventing it is executed by using an optional appropriate technique including a pinhole, a reflection mirror, the waveguide and a multi-mode interferometer. |
