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West Bengal, India

Chattopadhyay T.,Mechanical Operation Stage II
Optical Fiber Technology | Year: 2011

The design of all-optical 2 × 2 Terahertz Optical Asymmetric Demultiplexer (TOAD) based interferometric switch is proposed and described in this manuscript. Numerical simulation has been done to achieve the performance of the switch. Using this 2 × 2 TOAD based switch, cross-bar network architecture is designed. A reconfigurable logic unit is also proposed in this manuscript, which can perform 16-Boolean logical operations. © 2011 Elsevier Inc. All rights reserved.

A new and novel scheme for a high speed all-optical half adder based on single Quantum-dot semiconductor optical amplifier (QD-SOA) assisted Mach-Zehnder interferometer (MZI) is theoretically investigated and discussed. In this proposed scheme, pair of input data streams are simultaneously drive the switch to produce sum and carry. In this new design, only single switch can be utilized to design half adder circuit and no additional input beam is required other than two input signals. This design is simpler, smaller and compact than our previously proposed design . The impact of the peak data power as well as of the QD-SOAs current density and maximum modal gain on the ER, Q factor with current densities and electron relaxation times etc are explored and assessed by means of numerical simulations. © 1983-2012 IEEE.

Chattopadhyay T.,Mechanical Operation Stage II
Optics and Laser Technology | Year: 2010

Symmetric ternary number (radix=3) has three logical states (1-, 0, 1). It is very much useful in carry free arithmetical operation. Beside this, the logical operation using this type of number system is also effective in high speed computation and communication in multi-valued logic. In this literature all-optical circuits for three basic symmetrical ternary logical operations (inversion, MIN and MAX) are proposed and described. Numerical simulation verifies the theoretical model. In this present scheme the different ternary logical states are represented by different polarized state of light. Terahertz optical asymmetric demultiplexer (TOAD) based interferometric switch has been used categorically in this manuscript. © 2010 Elsevier Ltd. All rights reserved.

Chattopadhyay T.,Mechanical Operation Stage II
Applied Optics | Year: 2011

Logic units are the building blocks of many important computational operations likes arithmetic, multiplexer- demultiplexer, radix conversion, parity checker cum generator, etc. Multifunctional logic operation is very much essential in this respect. Here a programmable Boolean logic unit is proposed that can perform 16 Boolean logical operations from a single optical input according to the programming input without changing the circuit design. This circuit has two outputs. One output is complementary to the other. Hence no loss of data can occur. The circuit is basically designed by a 2 × 2 polarization independent optical cross bar switch. Performance of the proposed circuit has been achieved by doing numerical simulations. The binary logical states (0,1) are represented by the absence of light (null) and presence of light, respectively. © 2011 Optical Society of America.

A flip-flop (FF) is a kind of latch and the simplest form of memory device, which stores various values either temporarily or permanently. Optical FF memories form a fundamental building block for alloptical packet switches in next-generation communication networks. An all-optical clocked delay FF using a single terahertz optical asymmetric demultiplexer-based interferometric switch is proposed and described. Numerical simulation results are also reported. © 2010 Optical Society of America.

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