Bifurcation Analysis of the Voltage Controlled Photosensitive Chaotic Oscillator

A photosensitive chaotic oscillator which can be controlled with light illumination under various control voltage levels is proposed. The oscillator consists of a photodiode for the light input, clock switches and capacitors for the sample and hold function, a nonlinear function that creates an adjustable chaos map, and a voltage shifter that adjusts the output voltage for feedback. After optimizing the photodiode sub-circuit by using an available photodiode model in PC-based simulation program with integrated circuit emphasis to obtain a suitable output, the full chaotic circuit is verified with standard 0.6-μm complementary metal oxide semiconductor parameters. Chaotic dynamics are analyzed as a function of the light intensity under different control voltage levels. The time series, frequency spectra, transitions in state spaces, bifurcation diagrams and the largest Lyapunov exponent are improved.