In the above mentioned embodiment of the optical waveguide structure according the third aspect of the present invention{HEAD ~ , preferably, the second contact point} and the third contact point are located on a second perpendicular line, which is parallel to the reference perpendicular line and placed on the coupling side relative to the reference perpendicular line; and further comprising {TAIL ~ an intermediate core} between the reference perpendicular line and the second perpendicular line 