Patent ID: 7664353

Claim:
A method of making an optical waveguide structure having a first waveguide provided with the opposite ends A and B, a second waveguide with the opposite ends C and D, a third waveguide with the opposite ends E and F, and a coupling waveguide having its first beam incoming/outgoing end connected to the end B of the first waveguide and its second beam incoming/outgoing end connected to the end C of the second waveguide and the end E of the third waveguide, the method comprising a step of: longitudinally dimensioning the first waveguide and the coupling waveguide so that a peak component in intensity of a beam of light can abaxially transit the end A of the first waveguide while the peak component in intensity of the beam of light containing optical components in high-order modes can transit the second beam incoming/outgoing end of the coupling waveguide on and along its axis.