• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.41 no.6
• /
• pp.43-51
• /
• 2004

An optical parallel modified signed-digit(MSD) number adder system is proposed by using triple rail-coding input patterns and serial arrangement method of symbolic substitution. By combing overlapped arithmetic results. which are produced by encoding MSD input as triple rail-coding patterns. into the same patterns, symbolic substitution rules are reduced and also by using serialized and space-shifted input patterns in optical experiments, the optical adder without space-shifting operation, NOR operation and threshold operation is implemented.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.17 no.12
• /
• pp.1484-1493
• /
• 1992

In this paper, we propose the polarization coding of optical logic gates using filters and LCTV's, and represent the real-time system of an optical parallel adder to improve a carry propagation delay time. We fabricated a polarization filter for the polarization coding of a cell and an electrical system instead of an optical flip-flop which was necessary to an optical parallel adder. We used an optical fiber to play a part of decoding mask and interconnections in an optical parallel adder. The experimental results show that the polarization coding of a cell can represent 16 optical logic functions and that the implemented optical parallel adder can operate in real-time.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.18 no.6
• /
• pp.871-880
• /
• 1993

Conventional binary addition rules require a carry formation and propagation to the most significant bit, and lead to serial addition. Thus, the carry progapation in a binary addition stands as a hindrance to the full utilization of parallelism optics offers, Optical adders using a modified signed-digit(MSD) number system have been proposed to eliminate the carry propagation chain states to represent the three possible digits of MSD number system must encode three different states to represent the three possible digits of MSD. In the paper, we propose the design of a parallel optical adder based on 2-bit addition rules using the method of symbolic substitution(SS).

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.35D no.10
• /
• pp.107-115
• /
• 1998

A multiplier bit-pair recoding technique derived from Booth algorithm is used as an effective method that can carry out a fast binary multiplication regardless of a sign of both multiplicand and multiplier. In this paper, we propose an implementation of an optical high-speed multiplier which consists of a symbolic substitution adder and an optical multiplication algorithm, which transforms and enhances the multiplier bit-pair recoding algorithm to be fit for optical characteristics. Specially, a symbolic substitution addition rules are coded with a dual-rail logic, and so the complement of the logic of the symbolic substitution adder is easily obtained with a shift operation because it is always present. We also construct the symbolic substitution system which makes superposition image by superimposing two shifted images in a serial connection and recognizes a reference image by feeding this superimposed image to a mask. Thus, the optical multiplier, which is compared with a typical system, is implemented to the smaller system by reducing the number of optical passive elements and the size of this system.

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 1992.06a
• /
• pp.396-400
• /
• 1992

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.1
• /
• pp.269-280
• /
• 1996

We proposed a symbolic substitution method based on an optical correlator for an optical parallel addition. In the proposed symbolic substitution method, we used redundant binary number of the symbolic substitution rules as a number system and chose MAC3E filter which had very low sidelobes and good correlation peak compared with SDF filter as the optical correlation filter. We encoeded input numbers property to increase the discrimination capability and divided inpt patterns into 5 groups of the same addition results to minimize the number of symbolic substitution rules. Through the computer simulation, we confirmed the proposed method was suitable to implement the optical parallel adder.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.18 no.9
• /
• pp.1248-1256
• /
• 1993

The propagation and delay properties in opical fiber are particularly attractive because digital signal processing and conventional analog signal processing techniques such as those using surface acoustic wave devices are limited In their usefulness for signal bandwidth exceeding one or two GHz, although they are very effective at lower frequencies. Since an accurate, low loss and short time delay elements can be obtained by using such an optical fiber, optical signal precessing has attracted much attention for high speed and broad-band signal precessing in particular channel separation filtering for optical FDM signals. In this paper, we consider a coherent optical lattice filter, which uses coherent light sources and consists of directional couplers and optical fiber delay elemnts. The optical fiber fitters are more restricted than the usual digital filters. The reasons are as follows. 1) the coupling coefficients of directional couplers are restricted to the number between 0 and 1. 2) optical signal E(complex amplitude) is divided into J If-$\boxUl$ and J L/7$\div$$\boxUl$ at the directional coupler. Considering these restrictions and in this case all the coupling coefficients of summing and branching elements are set to be equal, we have given design formulae for optical lattice filter, which make the best use of optical signal energy.