**3.2.1 XOR and OR logic gates**

The input signals I1 and I2 are applied to the port 1 and 2 and the XOR gate outputs is taken from the output port 1. I1 and I2 are equal to P0. The reflected input signal I1 from the mirror interfered with either reflected signal or transmitted signal of I2 at the splitter. Either destructive or constructive interference are obtained at port 1 or 2 respectively depending on their phase difference. When both the input signals are same the output of XOR gate is zero and both are different the output is one.

In the case of OR gate, the input signals are combined and applied to the input port 2 and the output is taken from the output port 1. When both the signals are zero the output is zero and if any one of the input is high, the output is also high. To validate this theoretical prediction, steady state electromagnetic field distribution is simulated using FDTD method. Rsoft FullWAVE software is used to simulate logic gate functions. The field distributions of XOR and OR logic gates are shown in Figure 6 and their corresponding truth table is shown in Table 1.

Fig. 6. Electromagnetic field distributions of XOR logic gates. (a) & (b) any one of the input signal is applied (c) both input signals are excited simultaneously

Fig. 7. Field distributions of OR logic gates. a) any one of the input signal is applied b) both input signals are excited simultaneously

and it is found to 0.04 femtosecond. The calculated area is surrounded by a Perfectly

The input signals I1 and I2 are applied to the port 1 and 2 and the XOR gate outputs is taken from the output port 1. I1 and I2 are equal to P0. The reflected input signal I1 from the mirror interfered with either reflected signal or transmitted signal of I2 at the splitter. Either destructive or constructive interference are obtained at port 1 or 2 respectively depending on their phase difference. When both the input signals are same the output of XOR gate is

In the case of OR gate, the input signals are combined and applied to the input port 2 and the output is taken from the output port 1. When both the signals are zero the output is zero and if any one of the input is high, the output is also high. To validate this theoretical prediction, steady state electromagnetic field distribution is simulated using FDTD method. Rsoft FullWAVE software is used to simulate logic gate functions. The field distributions of XOR and OR logic gates are shown in Figure 6 and their corresponding truth table is shown

(a) (b) (c)

signal is applied (c) both input signals are excited simultaneously

input signals are excited simultaneously

Fig. 6. Electromagnetic field distributions of XOR logic gates. (a) & (b) any one of the input

(a) (b)

Fig. 7. Field distributions of OR logic gates. a) any one of the input signal is applied b) both

Matched Layer (PML) boundary.

**3.2.1 XOR and OR logic gates**

in Table 1.

**3.2 Realization and simulation results of logic gates** 

zero and both are different the output is one.


Table 1. Truth table for XOR and OR gate
