Numerical Optimization Technique for the Optimal Design of the Surface Plasmon Grating Coupler
C. Caiseda1 V. Aksyuk2 I. Griva3
1Inter American University of Puerto Rico, Bayamon, PR, USA
2National Institute of Standards and Technology, Gaithersburg, MD, USA
3George Mason University, Fairfax, VA, USA
The optimal design of the grating coupler for surface plasmon generation is revisited for its interdisciplinary importance in the efficient use of energy, and the strong dependence of the energy convergence rate of the system on the design. This work contributes a comprehensive gradient based numerical optimization technique to optimize both geometry of the grating and parameters of the Gaussian beam simultaneously. The method modifies all geometrical boundaries of each groove independently in a fixed mesh. The efficiency of energy conversion between the Gaussian beam and the plasmon is maximized. The conversion rate of the optimal design is significantly greater than the initial uniform design. Results show the practical value of these tools to be used on a n-grooves grating.