Odd and even number detection is an important mathematical operation. Generally when any number divisible by 2 then it is called even number, otherwise it is odd number. Division by 2 can be easily obtained by putting a point before least significant bit (LSB) of any binary number. As an example a number (27)10 = (11011)2 when divided by 2 its result will be (1101.1)2 = (13.5)10. Hence when we find the fractional bit as logic-1 we can say that the number is odd, otherwise it is even. This operation can be obtained by using a demultiplexer. Here we have developed an optical circuit which can divide any binary integer number by 2, apart from that its 1’s complement can also be obtained from the circuit. Both of the result can be obtained simultaneously. Terahertz optical asymmetric demultiplexer (TOAD) based generally switch assumes a vital part to plan this n-bit circuit. Numerical simulations are done to urge the exhibition of the circuit.