Implementation of optical and optoelectronic circuits

InTech eBooks, 2013

rays of optical detectors and light emitters which send and receive data directly out from the chip area. Honeywell has developed such devices with VCSEL diodes (vertical surface emitting laser diodes) and metal-semiconductor-metal photo-detectors in research project [4]. This allows the realization of stacked 3-D chip architecture in principle. The main problems are not the manufacturing and operating of single devices but the combination of different passive optical elements with active optoelectronic and electronic circuits in one system. This requires sophisticated mounting and alignment techniques which allow low mechanical tolerances and the handling of thermal problems. At present the situation for smart detector circuits is much easier. They can be regarded as a subset of OE-VLSI circuits because they consist only of arrays of photo-detectors with corresponding evaluation circuit for analogue to digital converting. Optical detectors based on PN or PIN photodiodes can be monolithically integrated with digital electronics in silicon what simplifies the design enormously compared with OE-VLSI circuits that in addition contain sender devices realized in GaAs technologies. Furthermore smart detector circuits can be manufactured in nearly every semiconductor fabric. Smart detectors or smart optical sensors show a great application field and market potential. Therefore our approach favors a smart pixel like architecture combining parallel signal detection with parallel signal processing in one circuit. Each pixel has its own PE what guarantees the fastest processing.

IET Circuits, Devices & Systems, 2011

Elementary blocks, performing logic operations, are the building elements for more complex subsystems implementing all-optical digital processing. They can potentially enable next generation optical networks and optical computing, overcoming the limitations of the electronics bandwidth, also guaranteeing scalability, transparency, easy reconfigurability and modularity. Finally, integrated technologies can reduce power consumption, footprint and cost.

Japanese Journal of Applied Physics, 1990

A novel method of optical data storage was proposed using the rotation of polarization. The optical data was recorded as a chiral structure formed in a film made of an azobenzene copolymer using elliptically polarized light irradiation. The elliptically polarized light of a reading light was digitized into two states, ''0'' and ''1''. The initial state is defined as ''0'', while state ''1'' is observed by an optical rotation of the reading light, which is achieved by the photoinduced chiral structure formation. The recording characteristics were investigated by varying the intensity of the recording light and the recording time. Since the chiral structure was erased by circularly polarized light, state ''1'' could be reversed to state ''0''. The possibility of using our proposed method for achieving next-generation rewritable, multilevel, and parallel optical data storage was discussed.

Photonic Devices and Algorithms for Computing IV, 2002

A major research area is the representation of knowledge for a given application in a compact manner such that desired information relating to this knowledge is easily recoverable. A complicated procedure may be required to recover the information from the stored representation and convert it back to usable form. Coder/decoder are the devices dedicated to that task. In this paper the capabilities that an Optical Programmable Logic Cell offers as a basic building block for coding and decoding are analyzed. We have previously published an Optically Programmable Logic Cells (OPLC), for applications as a chaotic generator or as basic element for optical computing. In optical computing previous studies these cells have been analyzed as full-adder units, being this element a basic component for the arithmetic logic structure in computing. Another application of this unit is reported in this paper. Coder and decoder are basic elements in computers, for example, in connections between processors and memory addressing. Moreover, another main application is the generation of signals for machine controlling from a certain instruction. In this paper we describe the way to obtain a coder/decoder with the OPLC and which type of applications may be the best suitable for this type of cell.

Journal of Optical Communications, 1991

Using silicon control rectifier (SCR), light dependent resistance (LDR) and light emitting diode (LED) fundamental optical logic NOT, AND, NAND, OR and NOR elements have been proposed. Because of simple structure and operation it is possible to design optical decoders, optical amplifiers etc. Other futuristic scope of the elements has also been discussed.

Journal of the Optical Society of Korea, 2008

Applied Optics, 1984

A general technique is described for implementing sequential logic circuits optically. In contrast with semiconductor integrated circuitry, optical logic systems allow very flexible interconnections between gates and between subsystems. Because of this, certain processing algorithms which do not map well onto semiconductor architectures can be implemented on the optical structure. The algorithms and processor architectures which can be implemented on the optical system depend on the interconnection technique. We describe three interconnection methods and analyze their advantages and limitations.

The proposed work presents a new structure that can be used as reconfigurable optical logic gates. This structure is constructed in a two dimensional (2D) photonic crystals (PhCs). Logic gates like AND, NOT and NOR are realized by using the proposed structure. These optical logic gates are constructed in 6 µm * 6 µm in 2D PhCs square lattice with a lattice constant a=0.648 µm. All the gates are realized by creating structural disorders in the cross-waveguide geometries of 2D PhCs. The several performance parameters are examined using this structure and observed that proposed structure has reduced size, fast response time of 0.46ps, high bit rates of 2.14Tbits/sec and better contrast ratio of 8.6dB against the existing designs. The signal amplitude larger than 0.5 arbitrary units (a.u.) and less than 0.1 (a.u.) at output are considered as logic ‘1’ and ‘0’ respectively. The plane wave expansion (PWE) is utilised to get the band gap for this logic gate 2D PhC structure and the finite ...

2015 International Conference on Circuits, Power and Computing Technologies [ICCPCT-2015], 2015

The development in the field of nanometer technology leads to minimize the power consumption of logic circuits. Reversible logic design has been one of the promising technologies gaining greater interest due to less dissipation of heat and low power consumption. Recently, in the literature, reversible logic gates and combinational circuits have been proposed in optical domain using Semiconductor Optical Amplifier (SOA) based Mach Zehnder interferometer (MZI) switches due to its significant advantages such as high speed, low power, fast switching and ease of fabrication. Optical reversible designs have used ad-hoc approaches and require high cost in terms of MZI switches, Beam Splitters (BS), and Beam Combiners (BC) as well as optical delay. In this work, an optical reversible MNOT gate and all-optical realization of 4×4 Toffoli Gate have been proposed which is used in all-optical realization of optimized reversible combinational circuits. A general design approach to realize all-optical reversible circuits based on MZI switches has been proposed first time in the literature. Optimized all-optical reversible 2×1 multiplexer and full adder circuits have been designed using these proposed gates and design approach. All-optical reversible designs of 4×1 multiplexer, 1×4 Demultiplexer and 3to8 Decoder circuits have also been presented in this work first time in the literature. Our results have shown significant improvements over existing designs in terms of MZI switches, BS, BC and optical delay.

Journal of the Optical Society of America A, 2009

We introduce a novel all-optical logic architecture whereby the gates may be readily reconfigured to reprogram their logic to implement (N)AND/(N)OR/X(N)OR. A single gate structure may be used throughout the logic circuit to implement multiple truth tables. The reconfiguration is effected by an optical reference signal. The reference may also be adapted to an arbitrary Boolean complex alphabet at the gate logic inputs and calibrated to correct gate imperfections. The all-optical gate structure is partitioned into a linear interferometric front end and a nonlinear back end. In the linear section, two optical logic inputs, along with a reference signal, linearly interfere. The nonlinear back end realizes a phase-erasure (or phase-reset) function. The reconfiguration and recalibration capabilities, along with the functional decoupling between the linear and nonlinear sections of each gate, facilitate the potential aggregation of large gate counts into logic arrays. A fundamental lower bound for the expended energy per gate is derived as 3h + kT ln 2 Joules per bit.

Optics Communications, 2010

Photon being the ultimate unit of information with unmatched speed and with data package in a signal of zero mass, the techniques of computing with light may provide a way out of the limitations of computational speed and complexity inherent in electronics computing. Information processing with photon as information carrying signal has shown a high level potentiality through the researches in last few decades. The driving force behind this evolution has been the utilization of interferometric configurations that employ a semiconductor optical amplifier (SOA) as the nonlinear element in combination with cross-phase modulation to achieve switching by means of light. Here, in this paper we present an all-optical circuit of programmable logic device (PLD) with the help of SOA-MZI (Mach–Zehnder interferometer) based optical tree-structured splitter. Numerical simulation result confirming described method is reported here. This paper also explains the applicability of this scheme to perform logical and arithmetic operations in all-optical domain.

Applied Optics, 1989

Cascadable optically nonlinear arrays of logic devices interconnected with space invariant optical components are proposed for the core memory of a digital computer. Access time to any portion of the memory is O(log 2 N) gate delays for logic devices with fan-in and fan-out of two, where Nis the size of the memory in bits. The cost of the design in switching components is near minimal for a random access memory (RAM) between one and two components per stored bit of information depending on the size of the memory. The design is extensible to very large RAMs, although parallel access memory is preferred to a RAM configuration for large memories due to the parallel access capability of the optical design.

Optical and Quantum Electronics

Arithmetic logic circuit (ALC) is the basic need of any combinational circuits but traditional digital circuits have limitations in terms of switching speed and power loss. In this paper, we have implemented an optical universal one-bit ALC by utilizing the electro-optic effect of Titanium-diffused lithium niobate (Ti-LiNbO 3) based Mach-Zehnder interferometers for high-speed processing combinational circuits. The extinction ratio of proposed design is highest for a 1-bit multiplier, which is 10.10 dB, and insertion loss of 0.362 dB is achieved for borrow logic. The beam propagation method has been used for the modeling and simulation of the proposed design at 1330 nm wavelength. Mathematical computation has been done for the proposed structure and further results were verified by MATLAB simulation.

2011

This research paper is about advancement in Optical Computing an emerging field of computer design and hardware with very fast speed and performances. The optical Computing (also known as Photonic computing) is a technique based on photons of visible light or infrared region rather than Electrons flowing in electric current which are used to perform digital Computations using electronic logic gates. In this technique we are using logic gates which will show the logic transition using photons of visible light which forms the basis of our research. We studied here that we can achieve a logic gate transition through photons of light employed using chemical compounds which behalves accordingly to incident photons of light on it. This photonic logic will be used to make optical transistors. This will in turn used to make processors working on the principal of light rather than on the principal of electric current.

1999

We have developed an optically reconfigurable field programmable gate array (OFPGA). The OFPGA integrated circuit is designed for high-speed configuration in systems based on a reconfigurable computing paradigm [1]. In these environments, the computation resources provided by the FPGA reused in multiple configurations throughout a single application program. Example applications are image and signal processing, data compression and database operations. In these applications, the same FPGA could be used to perform floating-point operations, histogramming, and query processing .