Design and Modeling of 1 Gbps Directed Optical XOR/OR Gates Using Integrated Semiconductor Ring Lasers

Effect of Nonlinearities on Directed Optical Logic Gates Using Integrated Semiconductor Ring Lasers

Abstract: Nonlinearities in the semiconductor ring laser (SRL) are incorporated in the analysis of directed optical logic gates and their effects on the output are studied. The paper discusses the effects of gain medium linewidth, internal quantum efficiency and self and cross gain saturation on the output of directed optical NOT gate implemented using SRLs.

All-optical logic based on silicon micro-ring resonators

Abstract: We demonstrate all-optical logic in a micron-size silicon ring resonator based on the free-carrier dispersion effect in silicon. We show AND and NAND operation at 310 Mbit/s with ∼10-dB extinction ratio. The free-carrier-lifetime-limited bit-rate can be significantly improved by active carrier extraction.

Operating regimes of GaAs-AlGaAs semiconductor ring lasers: experiment and model

Abstract: Theory and experiments of single-mode ridge waveguide GaAs-AlGaAs semiconductor ring lasers are presented. The lasers are found to operate bidirectionally up to twice the threshold, where unidirectional operation starts. Bidirectional operation reveals that just above threshold, the lasers operate in a regime where the two counterpropagating modes are continuous wave. As the injected current is increased, a new regime appears where the intensities of the two counterpropagating modes undergo alternate sinusoidal oscillations with frequency in the tens of megahertz range. The regime with alternate oscillations was previously observed in ring lasers of the gas and dye type, and it is here reported and investigated in semiconductor ring lasers. A theoretical model based on a mean field approach for the two counterpropagating modes is proposed to study the semiconductor ring laser dynamics. Numerical results are in agreement with the regime sequence experimentally observed when the injected current is increased (i.e., bidirectional continuous-wave, bidirectional with alternate oscillations, unidirectional). The boundaries of the different regimes are studied as a function of the relevant parameters, which turn out to be the pump current and the conservative and dissipative scattering coefficients, responsible for an explicit linear coupling between the two counterpropagating field modes. By a fitting procedure, we obtain good numerical agreement between experiment and theory, and also an estimation for the otherwise unknown scattering parameters.

All optical XOR logic gates: technologies and experiment demonstrations

Abstract: This article reviews the current status and technologies of all-optical XOR gates. Various schemes with semiconductor optical amplifiers, particularly those associated with interferometric structures, are discussed and compared. Finally, the applications of all-optical XOR gates to emerging networks are explored, and the future direction is outlined.

All-Optical Multiple Logic Gates Based on Spatial Optical Soliton Interactions

Abstract: In this letter, all-optical logic gates with attraction and repulsive interactions of coherent spatial optical solitons have been designed in a bulky nonlinear Kerr medium. The logic gates comprise logical AND and OR gates by the attraction of two obliquely propagating inphase spatial optical solitons and logical NOR and XNOR gates based on repulsive interaction among three out of phase spatial optical solitons. The numerical results show that soliton interactions perform a high contrast power level between ON/OFF states. The proposed model is applicable to design phase-modulated logical gates too. The simplicity and ease for fabrication of the proposed logic gates would be a potential key component for the future of all-optical logical photonic devices and computational photonic circuits.

Performance Evaluation of Integrated Semiconductor Ring Laser Gyroscope

Abstract: We present a mathematical analysis and comparison of the performance of integrated on-chip semiconductor ring laser gyroscope (SRLG) fabricated using GaAs/AlGaAs and InP/InGaAsP technologies. The performance parameters of the gyro are modeled in terms of fundamental material, waveguide, and resonator parameters. In addition to this, influence of phenomena specific to semiconductor lasers such as nonlinear coupling, spatial hole burning, gain grating formation, and carrier induced index change on the gyro performance is also included. The analysis helps in identifying critical parameters, which must be optimized to improve the gyro performance.Best achievable performance of integrated SRLG is calculated, and design modifications are suggested to enhance it for high-performance military applications.