Design of incrementer and decrementer device for optical computing

Abstract

Data communication around the whole globe has seen an enormous increase in the exchange of data across the networks. This has urged the need of optical communication systems that can provide the desired bandwidth. This paper is a step to the path of building such optical processing elements. The paper presents optical designs of a 3-bit incrementer and a 3- bit decrementer logic function. The two optical circuits increment or decrement each 3-bit input binary number by unity. The optical designs have been implemented using the LiNbO3 based Mach-Zehnder Interferometer (LNMZI) electrooptical switches. The incrementer circuit has employed just five LNMZIs and the decrementer circuit has only six LNMZIs. The optical circuits have been designed and tested using beam propagation method (BPM). A critical analysis of the two designs has been performed by calculation of the important performance metric parameters like extinction ratio (ER), contrast ratio (CR), insertion loss (IL). The incrementer/decrementer shows best values of ER, CR and IL as 31.43 dB, 35.71 dB and 0.95 dB respectively. The calculated parameters have been found within the acceptable limits which support the feasibility of the design.