Optical binary coded ternary arithmetic and logic

Advanced time-resolved absorption spectroscopy with an ultrashort visible/near IR laser and a multi-channel lock-in detector

Ultrashort visible-near infrared (NIR) pulse generation and its applications to ultrafast spectroscopy are discussed. Femtosecond pulses of around 800 nm from a Ti:sapphire laser are used as a pump of an optical parametric amplifier (OPA) in a non-collinear configuration to generate ultrashort visible (500-780 nm) pulses and deep-ultraviolet (DUV, 259-282 nm) pulses. The visible-NIR pulses and DUV pulses were compressed to 3.9 fs and 10.4 fs, respectively, and used to elucidate various ultrafast dynamics in condensed matter with a sub-10 fs resolution by pump-probe measurements. We have also developed a 128-channel lock-in amplifier. The combined system of the world-shortest visible pulse from the OPA and the lock-in amplifier with the world-largest channel-number can clarify the sub-10 fs-dynamics in condensed matter. This system clarified structural changes in an excited state, reaction intermediate, and a transition state. This is possible even during molecular vibration and reactions via a real-time-resolved vibronic spectrum, which provides molecular structural change information. Also, ultrafast dynamics in exotic materials like carbon nanotubes, topological insulators, and novel solar battery systems have been clarified. Furthermore, the carrier-envelope phase in the ultrashort pulse has been controlled and measured.

Development of Ultrashort Pulse Lasers for Ultrafast Spectroscopy

Principles and information obtained by ultrafast spectroscopy and scheme of optical parametric amplifier are discussed. Realization of ultrashort visible and ultraviolet lasers based on the parametric processes are discussed.

Multifunctional Graphene/DNA-Based Platform for the Construction of Enzyme-Free Ternary Logic Gates

In this work, we have successfully realized multivalued logic circuits including ternary INHIBIT and ternary OR logic gates in an enzyme-free condition by integration of graphene oxide and DNA for the first time. Compared to the binary logic gate with two states of "0" and "1", the multivalued logic gate contains three different states of "0", "1", and "2", which can increase the information content in a system and further improve the ability of information processing. Such types of multivalued logic operations provide a wider field of vision toward DNA-based algebra logical operations to make applications more accurate with complexity reduction and accelerate the development of advanced logic gates.

Compact parallel optical modified-signed-digit arithmetic-logic array processor with electron-trapping device

A compact two-step modified-signed-digit arithmetic-logic array processor is proposed. When the reference digits are programmed, both addition and subtraction can be performed by the same binary logic operations regardless of the sign of the input digits. The optical implementation and experimental demonstration with an electron-trapping device are shown. Each digit is encoded by a single pixel, and no polarization is included. Any combinational logic can be easily performed without optoelectronic and electro-optic conversions of the intermediate results. The system is compact, general purpose, simple to align, and has a high signal-to-noise ratio.

Redundant binary number representation for an inherently parallel arithmetic on optical computers

A simple redundant binary number representation suitable for digital-optical computers is presented. By means of this representation it is possible to build an arithmetic with carry-free parallel algebraic sums carried out in constant time and parallel multiplication in log N time. This redundant number representation naturally fits the 2's complement binary number system and permits the construction of inherently parallel arithmetic units that are used in various optical technologies. Some properties of this number representation and several examples of computation are presented.

Modified-signed digit arithmetic using an efficient symbolic substitution

An efficient symbolic substitution scheme for modified-signed digit arithmetic operations is introduced. In this technique, an additional bit is used along with each pair of the input bits so that the nth additional bit is a characteristic of the (n - 1)th pair of input bits. The truth table minimization thereby shows that relatively fewer minterms are to be included in the corresponding optical content-addressable memory.

Polarization-encoded optical shadow-casting scheme: design of multioutput trinary combinational logic units

The input encoding algorithm of the polarization-encoded optical shadow-casting (POSC) scheme is modified to include the design of trinary combinational logic units. For illustration, the modified algorithm is deterministically employed in the design of trinary adders. Two design approaches are examined for identifying the constraints and flexibilities that are encountered depending on whether the zero-output conditions are considered. The more complicated POSC overlap equations are handled by incorporating LED source encoding to the input encoding process.

Conditional symbolic modified signed-digit arithmetic using optical content-addressable memory logic elements

A new conditional symbolic substitution rule for modified signed-digit arithmetic computation is introduced. Using this substitution rule, the numbers to be added or subtracted are first replaced by a pair of new equivalent strings, which in a second step are then subject to another substitution to generate both the addition or subtraction result and its complement. For an optical implementation, a holographic contentaddressable memory is used. Correspondingly, the input encoding, the logic reduction, and the optical processing techniques are described.