Patent ID: 7680370

Claim:
An optical wavelength coupler comprising: a multi-mode waveguide ( 2 ) having a thickness (d) and a width (W MM ) determined by wavelengths (λ 1 ,λ 2 ) of a first or second optical signal, a refractive index (n) of the multi-mode waveguide, and an interference on the multi-mode waveguide, and having a length (L MM ) determined by a distance in which self-images or pseudo self-images of the first optical signal (λ 1 ) and the second optical signal (λ 2 ) are formed, the multi-mode waveguide ( 2 ) distributing the first optical signal (λ 1 ) or the second optical signal (λ 2 ) inputted at one side of the multi-mode waveguide ( 2 ), with one or more self-images and pseudo self-images at periodic intervals in a proceeding direction, so as to output at its opposite side a predetermined optical power.