Two-dimensional square-lattice photonic crystal with rotated hollow square rods and rotated triangle rods

A two-dimensional (2D) square-lattice photonic crystal (PhC) with rotated hollow square rods and triangle rods comprising:

• PhC structure formed by unit cells arranged in a square-lattices;
• the lattice constant of the square-lattice PhC is a;
• the unit cell of said square-lattice PhC includes a high-refractive-index dielectric rotated hollow square rod, four high-refractive-index dielectric triangle rods and a low-refractive-index background dielectric, the outer contour of said rotated hollow square rod is a first rotated square rod, said first rotated square rod has the rotated angle α of 45 to 60 degrees and the side length b of 0.56a to 0.7a;
• a cross section of said rotated hollow square rod is a second rotated square rod, and said second rotated square rod has the rotated angle β of 30 to 55 degrees and the side length c of 0.276a to 0.49a;
• said triangle rods are four right-angle triangle rods, a cross section of said triangle rods are right-angle triangle, said four right-angle triangle rods positioned at the hollow square rod, and the vertex connecting lines of the four right-angle triangle rods form a third rotated square rod;
• said third rotated square rod has the rotated angle γ of 40 to 55 degrees and the side length d of 0.188a to 0.3472a;
• the hypotenuse connecting lines of the four right-angle triangle rods form a fourth rotated square rod;
• said fourth rotated square rod has the rotated angle ω of 26 to 50 degrees and the side length e of 0.173a to 0.382a.