Search

S-shaped bend waveguides are indispensable in planar light circuits to realize the lateral displacements and connections. High-density integrated optical circuits require S-shaped bend waveguides to be low loss and compact sized. In this paper, the loss mechanism of the S-shaped bend is briefly analyzed first, and then a novel scheme to optimize the waveguide bends is proposed. Using a modified random direction method, the random orthogonal axial gradient method (ROAGM), the configuration curves of the S-shaped bends fitted by polynomials are optimized. Numerical results show that the insertion losses of the optimized configuration curves are much smaller than those of the conventional cosine functions when the space requirement is strict.