Design and implementation of the one-step MSD adder of optical computer

Abstract

On the basis of the symmetric encoding algorithm for the modified signed-digit (MSD), a 7*7 truth table that can be realized with optical methods was developed. And based on the truth table, the optical path structures and circuit implementations of the one-step MSD adder of ternary optical computer (TOC) were designed. Experiments show that the scheme is correct, feasible, and efficient.

A parallel optical implementation of arithmetic operations

“…Different technologies can be used to implement this switching behavior. Like some of the recent optical processors [36,37,39], the presented processor can use polarized light and liquid crystals for switching: both light sources can produce horizontally polarized light and the cells that block the light can change the polarization direction of light 90 degrees using liquid crystals. Then vertically polarized light can be ignored as blocked.…”

“…Some of the past parallel optical processors use technologies like self-electro-optic effect devices (SEED) [61], electron trapping devices [62,63], liquid crystals [36,37], and spatial light modulators [64] for optical logic implementation and optical switching and modulation. Louri et al [64][65][66][67] and Choo et al [68] used such devices in their optical parallel database architectures.…”

“…One of the main problems of using nonlinear optical devices like those based on SEED for implementing optical logic gates, is their high energy consumption [69]. This is probably the reason for the preference of many of the recent optical processors for using liquid crystal for switching instead [35][36][37].…”

“…In the last few years, there seems to be growing interest in parallel optical computing; researchers are trying to use optical devices, like liquid crystal, to implement parallel arithmetic operations like addition [35][36][37] and to improve the performance of optical vector-matrix multiplication [29,[38][39][40][41].…”

All-optical polarization-encoded negabinary signed-digit adder designs using terahertz-optical-asymmetric-demultiplexer switches

“…On the other hand, an arithmetic optical computing system is more efficient when a non binary number representation is utilized to avoid the long carry/borrow bit propagation paths that exist during the binary arithmetic operations (Cherri, 1998;Chattopadhyay et al, 2009;Al-zayed & Cherri, 2010;Song & Yan, 2012). Examples of some non binary number representation are the multiple-valued number and the redundant signed-digit number, which permit parallel arithmetic operations.…”