Oscillations have been observed in numerous areas of science and engineering. Some typical oscillations relate to pendulums, business cycles, and neural dynamics. Nonlinearities lead to complex behaviors of oscillations, in particular the chaotic dynamics, which received significant attention since 1963, when Lorenz observed experimental chaos in a nonlinear weather model. Chaotic oscillators exhibit rich dynamics and have been found in numerous engineering applications, including cryptography, encryption, secure communications, random signal generator, through-wall radar, and robotics.

Various chaotic oscillators have been reported in the literature in the last three decades. Meanwhile, there are many hot topics of interest in chaos literature. For instance, we have discovered new chaotic oscillators with special features (like multistability, megastability) and/or with novel phenomena (like hidden attractors, extremely large events). Experimental studies of oscillatory systems via simulations and circuits support us for understanding the modeling phenomena deeply, and also developing practical applications. Advanced techniques in different areas such as memristors, memristive devices, field programmable gate arrays‎ (FPGA), field-programmable analog arrays (FPAA), neural networks, and machine learning provide effective tools to study and implement chaotic oscillations. Moreover, there are still various challenging problems. For instance, there are still issues, in theory, experiments, control, as well as fractional-order chaotic models.

The aim of this Special Issue is to bring together original research articles discussing chaotic oscillators with modeling, bifurcation analysis, circuit design, or control applications. Review articles introducing the current state of the art are especially welcome.

Potential topics include but are not limited to the following:

• Bifurcation analysis and qualitative study of chaotic systems
• Chaotic oscillators and secure communications
• Chaotic oscillations in fractional-order differential equations
• Circuit design of chaotic oscillators
• Control and synchronization of chaotic oscillations
• Emerging technologies for implementing oscillators
• Experimental chaotic oscillations in practical systems
• Fractional-order chaotic oscillators and applications
• Hyperchaotic oscillators and applications
• Modeling, analysis and computational methods of chaotic oscillations
• Practical applications of chaotic oscillations
• Self-excited and hidden attractors in chaotic oscillators