An Improved Delay Time Of Optical Half-Adder Applying Nonlinear Photonic Crystals Technology

In the present investigation, we attempt to develop a new structure of optical half adder using nonlinear photonic crystal ring resonator. As a main advantage, the use of coupling between bus waveguide and ring resonator increases the power intensity of the output and opens a wider photonic band gap (PBG). In this design, in order to improve the optical characteristics of the designed half adder, the combination of interference-based defect and nonlinear Kerr effect is exploited, as well as logic function transmit power control, including radius and refractive index of coupling rods. As a result, the structure contrast ratio is valued between 12.74 dB and 16.33 dB, proportional to the output power, which varies between 1.7% to 5% and 88 % to 108% for logic level “0” and “1” respectively. Resulting a minimum threshold power around of
$0.3\ \mathrm{W}/\mu\mathrm{m}^{2}$
. Additionally, the suggested design can be taken into account for ultra-fast integrated circuits to assure their integration in optical communication networks. Plane wave expansion (PWE) and finite difference time domain (FDTD), two distinct numerical techniques, are applied to estimate the propagation modes and the output spectrum respectively.