| 摘要 |
PROBLEM TO BE SOLVED: To easily separate a mode even when a beam is a dispersing light beam having a large opening angle by making a first and a second mode beams incident on the boundaries of a first and a second optical waveguides with a specified incident angle and forming the boundary to be a shape for dividing the mode beam into 2n beams and propagating in a different direction. SOLUTION: A first optical waveguide (region A) having equivalent refractive indices of Ni1, Nj1 for a first and a second mode beam is connected to a second optical waveguide (region B) having equivalent refractive indices of Ni2, Nj2, Ni1<Ni2, Nj1<Nj2, both mode beams are made incident on the boundaries A, B with an incident angleαsatisfying the conditions: 0<|sinα|<(Ni1/Ni2), 0<|sinα&k<(Nj1/Nj2) and both mode beams are separated by utilizing the difference of the refractive angles. The boundary are formed by dividing the first and second mode beams into 2n (n is integer), preferably into two and propagating them in a different direction. |
