Optoelectronic Logic Functions Based on Reconfigurable SiC Multilayer Devices

WDM multilayered SiC/Si devices based on a-Si:H and a-SiC:H filter design are approached from a reconfigurable point of view. Results show that the devices, under appropriated optical bias, act as reconfigurable active filters that allow optical switching and optoelectronic logic functions development. Under front violet irradiation the magnitude of the red and green channels are amplified and the blue and violet reduced. Violet back irradiation cuts the red channel, slightly influences the magnitude of the green and blue ones and strongly amplifies de violet channel. This nonlinearity provides the possibility for selective removal of useless wavelengths. Particular attention is given to the amplification coefficient weights, which allow taking into account the wavelength background effects when a band needs to be filtered from a wider range of mixed signals, or when optical active filter gates are used to select and filter input signals to specific output ports in WDM communication systems. A truth table of an encoder that performs 8-to-1 multiplexer (MUX) function is presented.

Logic functions based on optical bias controlled SIC Tandem devices

The purpose of this paper is the design of an optoelectronic circuit based on a-SiC technology, able to act simultaneously as a 4-bit binary encoder or a binary decoder in a 4-to-16 line configurations and show multiplexer-based logical functions. The device consists of a p-i'(a-SiC:H)-n/p-i(a-Si:H)-n multilayered structure produced by PECVD. To analyze it under information-modulated wave (color channels) and uniform irradiation (background) four monochromatic pulsed lights (input channels): red, green, blue and violet shine on the device. Steady state optical bias was superimposed separately from the front and the back sides, and the generated photocurrent was measured. Results show that the devices, under appropriate optical bias, act as reconfigurable active filters that allow optical switching and optoelectronic logic functions development providing the possibility for selective removal of useless wavelengths. The logic functions needed to construct any other complex logic functions are the NOT, and both or either an AND or an OR. Any other complex logic function that might be found can also be used as building blocks to achieve the functions needed for the retrieval of channels within the WDM communication link. (C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

SYM-1, a program that detects symmetry of variable-valued logic functions /

Mode of access: Internet.

A planar geometrical model for representing multidimensional discrete spaces and multiple-valued logic functions /

Bibliography: p. 37-38.

Three transducers for one photodetector: essays for optical communications

Dissertation presented to obtain the PhD degree in Electrical and Computer Engineering - Electronics

Automated synthesis of delay-reduced Reed-Muller universal logic module networks

This paper presents a new approach to implement Reed-Muller Universal Logic Module (RM-ULM) networks with reduced delay and hardware for synthesizing logic functions given in Reed-Muller (RM) form. Replication of single control line RM-ULM is used as the only design unit for defining any logic function. An algorithm is proposed that does exhaustive branching to reduce the number of levels and modules required to implement any logic function in RM form. This approach attains a reduction in delay, and power over other implementations of functions having large number of variables.

Searching the hearts of graphene-like molecules for simplicity, sensitivity and logic

If quantum interference patterns in the hearts of polycyclic aromatic hydrocarbons (PAHs) could be isolated and manipulated, then a significant step towards realizing the potential of single-molecule electronics would be achieved. Here we demonstrate experimentally and theoretically that a simple, parameter-free, analytic theory of interference patterns evaluated at the mid-point of the HOMO-LUMO gap (referred to as M-functions) correctly predicts conductance ratios of molecules with pyrene, naphthalene, anthracene, anthanthrene or azulene hearts. M-functions provide new design strategies for identifying molecules with phase-coherent logic functions and enhancing the sensitivity of molecular-scale interferometers.

All-optical logic gates with 1550nm Fabry-Perot and distributed feedback semiconductor laser amplifiers

The optical bistability occurring in laser diode amplifiers is used to design an all-optical logic gate capable to provide the whole set of logic functions. The structure of the reported logic gate is based on two connected 1550nm laser amplifiers (Fabry-Perot and distributed feedback laser amplifiers).

Analysis of irregular behaviour on an optical computing logic cell

A new methodology to study irregular behaviours in logic cells is reported. It is based on two types of diagrams, namely phase and working diagrams. Sets of four bits are grouped and represented by their hexadecimal equivalent. Some hexadecimal numbers correspond to certain logic functions. The influence of the internal and external tolerances, namely those appearing in the employed devices and in the working signals, may be analysed with this method. Its importance in the case of logic structures with chaotic behaviours is studied.

Major and minor threshold functions of six variables /

Issued also as thesis (M.S.) University of Illinois.

Partially separable functions.

"Supported in part by Atomic Energy Commission contract AT(11-1)-1469."

: SiC Multilayer Photonic Structures with Self Optical Bias Amplification

Characteristics of tunable wavelength pi'n/pin filters based on a-SiC:H multilayered stacked cells are studied both experimental and theoretically. Results show that the device combines the demultiplexing operation with the simultaneous photodetection and self amplification of the signal. An algorithm to decode the multiplex signal is established. A capacitive active band-pass filter model is presented and supported by an electrical simulation of the state variable filter circuit. Experimental and simulated results show that the device acts as a state variable filter. It combines the properties of active high-pass and low-pass filter sections into a capacitive active band-pass filter using a changing photo capacitance to control the power delivered to the load.

SiC Multilayer Structures as Light Controlled Photonic Active Filters

Tunable wavelength division multiplexing converters based on amorphous SiC multilayer photonic active filters are analyzed. The configuration includes two stacked p-i-n structures (p(a-SiC:H)-i'(a-SiC:H)-n(a-SiC:H)-p(a-SiC:H)-i(a-Si:H)-n(a-Si:H)) sandwiched between two transparent contacts. The manipulation of the magnitude is achieved through appropriated front and back backgrounds. Transfer function characteristics are studied both theoretically and experimentally. An algorithm to decode the multiplex signal is established. An optoelectronic model supports the optoelectronic logic architecture. Results show that the light-activated device combines the demultiplexing operation with the simultaneous photodetection and self-amplification of an optical signal. The output waveform presents a nonlinear amplitude-dependent response to the wavelengths of the input channels. Depending on the wavelength of the external background and irradiation side, it acts either as a short- or a long-pass band filter or as a band-stop filter. A two-stage active circuit is presented and gives insight into the physics of the device.

Light-activated amplification in SiC Tandem devices: A capacitive active filter model

Characteristics of tunable wavelength pi'n/pin filters based on a-SiC:H multilayered stacked cells are studied both experimentally and theoretically. Results show that the device combines the demultiplexing operation with the simultaneous photodetection and self amplification of the signal. An algorithm to decode the multiplex signal is established. A capacitive active band-pass filter model is presented and supported by an electrical simulation of the state variable filter circuit. Experimental and simulated results show that the device acts as a state variable filter. It combines the properties of active high-pass and low-pass filter sections into a capacitive active band-pass filter using a changing capacitance to control the power delivered to the load.