6.1.1 Simulation Technique (SRR)
FDTD method is used to simulate the structure. S-parameters are extracted by using S-parameter analysis tool. In figure 1, unit cell is shown. The substrate thickness and width of metal wires are 250nm and 140nm respectively. Whereas, gap between the ring is 2000nm and the length of the outer wire is 147nm.
Figure 1. (a) Horizontal incident light and (b) Parameters
Figure 2 shows the simulation results of the Split Ring Resonators i.e. Transmission, Refractive index, permittivity and permeability. As it can be seen that permittivity and permeability show a negative result at around 9.7 THz. Which shows that, this structure contains the qualities of double negative metamaterials.
Figure 3 shows the simulation results of the Split Ring Resonators i.e. Transmission, permittivity, Refractive index and permeability by varying the width of the wires from 50nm – 140nm and keeping the length constant at 140nm. As it can be seen that with the change in width there is a change in the transmission and permittivity that shows that it is a Left-handed metamaterial. While there is no change in the permeability, but there is a change in refractive index by increasing the widths it goes more negative in nature.
Figure 4 shows the simulation results of the Split Ring Resonators i.e. permittivity, refractive index and permeability by changing the gap ‘g’ in the SRR structure. As it can be seen that by changing the gap ‘g’ from 500nm - 700nm there is a change in result, as it is moving to the left side while decreasing the gap.
Figure 5 shows the simulation results of the Split Ring Resonators i.e. permittivity, refractive index and permeability by keeping the lattice constant ax fixed and varying the ay from 1500nm – 2400nm. As it can be seen clearly that while increasing the lattice constant ax, there is a change in result and the waves are moving towards left direction with the increase in lattice constant ay.
Figure 6 shows the simulation results of the Split Ring Resonators i.e. permittivity, refractive index and permeability by keeping the lattice constant ay fixed and varying the ax from 2200nm – 2600nm. As it can be seen clearly that while decreasing the lattice constant ay, there is a change in result and the waves are moving towards left direction with the decrease in lattice constant ax.
Figure 2. (a) Transmission (b) Permittivity (c) Permeability (d) Refractive index
Figure 3. (a) Transmission (b) Permittivity (c) Permeability (d) Refractive index
Figure 4. (a) Permittivity (b) Permeability (c) Refractive index
Figure 5. (a) Permittivity (b) Permeability (c) Refractive index
Figure 6. (a) Permittivity (b) Permeability (c) Refractive index