Coupler structure optimization method

The invention provides a coupler structure optimization method, and relates to the field of integrated optoelectronic device design, and the method comprises the steps: determining a plurality of discrete initial control points of a corresponding side line of each waveguide in a coupling region of a coupler; fitting a plurality of corresponding initial control points on each waveguide sideline to form an initial sideline; and adopting first correlation operation to optimize the plurality of initial control points to obtain a plurality of target control points, and adopting second correlation operation to fit the plurality of target control points into a smooth target sideline to obtain the target shape of each waveguide. On the basis of the adiabatic coupler, a reverse design method is adopted, an adjoint optimization algorithm and B spline curve shape optimization are combined, and the waveguide shape is further optimized, so that the device has a smaller size, a higher bandwidth and a lower manufacturing pr