All optical half subtractor based on linear photonic crystals and phase shift keying technique

Abstract

In this work, the authors investigate the new structure of all optical half subtractor in a two dimensional photonic crystal based on wave interference and phase shift keying technique. The suggested structure is designed using 10 optical waveguides and one defect in the basic structure. The numeral methods such as plane wave expansion and finite difference time domain are used to analyze the proposed structure. According to obtained results, the rise and fall times, the working bit rate, the minimum and maximum values of the normalized power at ON and OFF states for output ports are 0.1 ps, 0.05 ps, 5 Tbit/s, 77 and 17%, respectively. According to results, high switching speed, compactness, low power consumption and ultra-fast operation are the main advantages of designed optical half subtractor compared with the previous structures.

A novel proposal for all optical 1-bit comparator based on 2D linear photonic crystal

“…In this method the optical device is constructed based on constructive and destructive interference phenomenon of optical beams. Many optical devices such as isolator, decoder, gates, adders, subtractors, comparators, convertors and multiplexer were made with this procedure [15][16][17][18][19][20][21][22][23][24][25]. The functional parameters of these optical devices including ON-OFF contrast ratio (CR), bit rate (BR), optical intensity (OI), fall, rise and delay times (T r , T f andT d ) and total footprint (TFP) were evaluated.…”