Design and optimization of 1×2 and 1×4Y-shaped beam splitters in GaSb-based 2D photonic crystals.

In this paper, we investigate the structural design of beam splitters with high total transmission efficiency in the two-dimensional (2D) GaSb (Gallium Antimonide)-based photonic crystals, and several optimal structures for 1 × 2 and 1 × 4 Y-shaped beam splitters have been provided. Using our proposed alternating iteration algorithm, by introducing several microstructures in the bend and Y-shaped junction areas to achieve topology optimization, the design of Y-shaped beam splitters with high total transmission efficiency at 1550 nm makes great progress. The splitter structures are designed on 2D GaSb-based photonic crystals with a triangular lattice of air holes immersed in the GaSb. All designs are simulated numerically and analyzed by using the finite element method. The optimized structures of 1 × 2 , 1 × 4 Y-shaped beam splitters show that our optimization technique is efficient and simple. And the total transmission efficiencies both over 7 2 % at output ports are obtained, which indicates that our method is relatively efficient to other methods in some related reports. [ABSTRACT FROM AUTHOR]