Presentation Preference: poster POLARIZATION ENCODED FOUR-VALUED ORDINARY INVERTER Tanay Chattopadhyay and Jitendra Nath Roy * Department of Physics, National Institute of Technology, Agartala, 799055, Tripura, India. Email:
[email protected],
[email protected] Abstract: The principle and possibilities of design of an all-optical four- valued ordinary Inverter circuit with the help of ultra-fast all-optical interferometric switch is proposed and described. Different polarized state of light represents the different 4-valued logical states. Simulation result confirming described methods and conclusion are given in this paper. 1. INTRODUCTION: Multi-valued logic is positioned as a technology that can execute arithmetic functions faster and with less interconnect than binary logic and can provide considerable relief of capacity constraints [1-3]. In binary logic there is just one inverter that changes a state into another state. An arithmetical approach to inverters in an m-valued logic in the literature is provided by the formula: x = (m-1)-y where y is the 'original' value and x is the 'inverted' value of y. There are 4! four-valued reversible inverters. In this present paper we propose and describe the alloptical circuit of polarization encoded one self reversing inverter (also known as ordinary inverter) with the help of Terahertz Optical Asymmetric Demultiplexer (TOAD) based interferometric switches.
3. RESULT AND DISCUSSION
Simulation is done for input bit pattern “0123 0123” and the corresponding output bit pattern is “3210 3210” and the data rate is 10.53 Gb/s. Insertion loss ,contrast ratio and extinction ratio of this circuit have been calculated. The theoretical model developed and the results obtained numerically are useful to future all-optical logic computing system. This quaternary inverter circuit can be exploited to design multi-valued flip-flop
2. DESIGNING OF ALL-OPTICAL QUATERNARY INVERTER CIRCUIT A quaternary Inverter truth table is shown in the Table-1 and the optical circuit is shown in Fig-1. The QNOT gate consists of two TOAD based switch S1 and S2 respectively. Here, the control signal (X) is taken as the quaternary input, which can take any one of the four quaternary logic states. Er3+ doped fiber laser source of 1549 nm and 1557 nm wavelength act as control signal and incoming signal respectively. Here, PC is polarization controller, AT is variable attenuater, CO is 2 × 2 3 dB coupler; CR is optical circulator, BPF is band pass filter; BC is beam combiner; TH is thresholders, PM is Power meter, DT is a Polarization detectorand ODL is Optical delay line.
Fig-2: Physical model of the QNOT circuit
Table-1: Truth inveretrer.
REFERENCES
table
of
ordinar
Input (X)
Output ( X )
0
3
1
2
2
1
3
0
quaternary
4. CONCLUSION
In this paper, the first time to our knowledge, we have proposed and described an optical circuit for quaternary inverter. The significant advantage of this scheme is that the logical operation, which can be performed, is alloptical in nature.
[1] S.L.Hurst, “Multiple-Valued Logic—Its Status and its Future”, IEEE Transactions on computers, C-33 (12), 1160-1179, (1984). [2] T.Chattopadhyay, J.N.Roy and A.K.Chakraborty, “Polarization encoded all-optical quaternary R-S flip-flop using binary latch”, Optics Communications, 282,1287-1293 (2009). [3] T.Chattopadhyay, C.Taraphdar and J.N.Roy, “Quaternary Galois field adder based all-optical multivalued logic circuits”, Applied Optics, 48(22), (2009), E35-E44.
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