In this paper, we are going to propose a novel structure of all-optical NOT, XOR and XNOR logic gates are presented using a two-dimensional photonic crystal (2D-PhC). This structure is optimized by varying the radius of the cavity, to obtain a quality factor Q = 1192, and also has several ports of entry and one port of output. The size of each structure is equal to 85.8 μm2. The contrast ratios for the structures proposed all-optical NOT, XOR and XNOR logic gates between levels “0” and “1” are, respectively, 25.08, 25.03, and 14.47 dB. The response time for the three logical gates is 8.33 ps, and the bit rate is calculated at about 0.12 Tbit/s, all simulations are based on both numerical methods such as finite difference time domain (FDTD) and plane wave expansion (PWE). Designed logic gates are characterized by low power consumption, compactness and easy integration.

In this paper, the use of the Kerr effect in a two-dimensional square lattice of In0.82Ga0.18As0.40P0.60 rods in photonic crystal proposes an ultra-compact all-optical NOT logic gate. The main device operation is based on the concept of all the optical switches. In our work, the novelty lies in the design of a new simple nonlinear ring based on the combination of silicon nano-crystal "Si–Nc/In0.82Ga0.18As0.40P0.60" materials that can be used. The contrast ratio and delay time for the proposed NOT logic gate are respectively 25.52 dB and 0.66 ps. The structure size is equal to 168 μm2. Designed logic gates are characterized by low energy consumption, high-speed response, compactness and easy integration. All simulations are based on Non-Linear-Finite Difference Time Domain (NL-FDTD) and Plane Wave Expansion (PWE) numerical methods.

All-optical logic gates are indispensable elements in optical devices and optical computing. Our logic gates are based on bidimensional photonic crystals, where the pillars radius and lattice constant are chosen in such a way that the logic gates are actuated at the wavelength of 1550 nm. The contrast ratios for the NOT, XOR, NOR, and XNOR gates are 26.82 dB, 26.77 dB, 8.34 dB, and 20.17 dB respectively. The response time of the different logic gates is approximately 8.5 ps, resulting in a data transmission rate of 0.117 Tb/s. One of the advantages of our study, from the logic gate NOT we could design all the other gates such as XOR, NOR, and XNOR.

Optical logic gates based on the Pockels effect are key components of light-wave communication networks and quantum computing because they are highly efficient and ultrafast. In this paper, we proposed a new hybrid platform of gallium arsenide and barium titanate (GaAs-BTO) for Ultraefficient Electro-Optic Tuning based on two-dimensional photonic crystals, the only proposed multifunctional structure is used to realize various very high-performance photonic logic gates such as BUFFER, NOT, AND, NAND, NOR, OR, XOR, XNOR. The functional parameters of these miniature logic gates are analyzed and optimized numerically by the FDTD method. The simulation results show that the contrast ratio is very high, with a very small footprint of 157 μm2, the response time is ultrafast 1 ps which corresponds to a bit rate of 1 Tbps.

In our work, we propose a novel temperature sensor design based on a two-dimensional (2D) photonic crystal resonant cavity structure designed to detect and monitor temperature under very harsh environmental conditions from 0 °C to 500 ºC. The sensitivity of the proposed structure is 109.8 pm/ºC, an ultra-high quality factor, high transmission efficiency and ultra-compact size. The characteristics of the proposed sensor under different temperatures are simulated using the Plane Wave Expansion (PWE) method and Finite Difference Time Domain (FDTD) method to calculate, respectively, the Photonic Band Gap (PBG) and transmission efficiency. The results obtained show that the wavelength of the resonant cavity increases linearly with increasing temperature. Our sensor is suitable for applications based on nanotechnology.