Open AccessAll-optical half adder based on cross structures in two-dimensional photonic crystals
Author(s) -
Qiang Liu,
Zhengbiao Ouyang,
Chong Wu,
Chung Ping Liu,
Jong C. Wang
Publication year - 2008
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.16.018992
Subject(s) - adder , xor gate , photonics , logic gate , photonic integrated circuit , optical computing , finite difference time domain method , digital electronics , optics , and gate , contrast ratio , photonic crystal , computer science , electronic circuit , electronic engineering , optoelectronics , physics , algorithm , engineering , cmos , quantum mechanics
We propose an all-optical half adder based on two different cross structures in two-dimensional photonic crystals. One cross structure contains nonlinear materials and functions as an "AND" logic gate. The other one only contains linear materials and acts as an "XOR" logic gate. The system is demonstrated numerically by the FDTD method to work as expected. The optimal operating speed without considering the response time of the nonlinear material, the least ON to OFF logic-level contrast ratio, and the minimum power for this half adder obtained were 0.91 Tbps, 16 dB and 436 mW, respectively. The proposed structure has the potential to be used for constructing all-optical integrated digital computing circuits.