Ultrafast All Optical Parity Generator and Checker Based on Quantum dot Semiconductor Optical Amplifier

All optical Majority gate using Quantum dot SOA based Tera hertz Optical Asymmetric Demultiplexer (TOAD)

“…In all optical logic processing still there are many unsolved challenges [2]. All optical logic implementations includes simple logic operations like OR, NOT, XOR etc [3], half adder [4], full adder [5], comparator [6], flip-flops [7], parity generator-checker [8], code converters [9], programmable logic array [10], canonical logic unit(CLU) [2] etc. Among these CLU and PLA together is very effective for implementation of different complex logic processors for high speed optical processing.…”

“…Equation (8) shows that whatever may be the input condition, output intensity of the high states are nearly same because only one term in the expreesion on the right hand side of equation( 7) becomes high at a time(Table 2). This improves the performance of the majority gate as discussed in the following section.…”

“…Similarly if we use C as input control and (ÃB+AB̃) as data signal to the QDSTOAD, the destructive port will generate logical output (ÃB+AB̃)C. Based on this simple principle the majority gate in terms of equation ( 8) is realized. Figure 2 describes such design of the majority gate which implements the equation (8). Three inputs A, B and C act as control power to the QDSOA-TOADS 1, QDSOA-TOADS 2, and QDSOA-TOADS 3 respectively.…”

“…The AND outputs of both QDSTOAD-1 and QDSTOAD-2 are combined and attenuated using variable optical attenuator(VOA-2) before combining it to the output of QDSTOAD-3. M is the final output of the majority gate based on equation (8).…”