Control And Synchronization Of Hyperchaos In Optical Parametric Oscillator

The dissertation mainly investigates the control and synchronization of hypechaos in degenerate optical parametric oscillator. At the same time, we also do a lot of study for anti-control of chaos in degenerate optical parametric oscillator(DOPO) and second hamonic generation(SHG). The research work can be classified into three parts: Controlling hyperchaos and synchronizing periodic states in the DOPO, synchronizing hypechaos in the DOPO and anti-control of chaos in the DOPO and SHGIn part one, firstly, the dynamic equation of the DOPO is deeply investigated and the stability of its stable solution is analyzed. It is found that DOPO can be in chaotic or hyperchaotic state at some conditions. The hyperchaos is successfully controlled by four methods—periodic parameter modulation, outer periodic signal paremeter modulation, mutual couple and outer optical field. Then we research periodic synchronization in the DOPOs and analyse synchronizing types and characteristics.In part two, Hyperchaotic synchronization of the DOPOs are investigated by three methods—unidirectional coupling driving, mutual couple and outer hyperchaotic signal paremeter modulation. Synchronization and inversed synchronization in the DOPOs can be realized because of phase modulator. We study the chaotic synchronization in DOPOs by hyperchaotic signals, which modulate parameters. Statistics have shown that two or more chaotic systems based on new dynamics can fulfill synchronization or inversed synchronization. We have also observed that the synchronizing states depend on different initial conditions and modulating coefficients. Under certain initial conditions, synchronization state tends to show spontaneous mutation in accordance with some points of the modulating coefficients.In part three, anti-control of chaos in the DOPOs and SHG are first put forward by four methods, which are period parameter modulation, unidirectional coupling driving, outer hyperchaotic signal paremeter modulation and mutual couple. Anti-control of chaos in the DOPOs and SHG are discussed with periodic parameter modulation. There are differentattrators because of different modulating coefficient in the DOPO. The greater the modulating coefficient, the greater output of the amplitude of the subharmonic mode. Anti-control of chaos in the DOPOs with unidirectional coupling driving, outer hyperchaotic signal paremeter modulating and mutual coupling methd respectively, the output intensity of the chaotic signal is different depending on the different coupling coefficient and modulating coefficient.hi the end, optic secure communication is investigated by using hyperchaotic signal of the DOPO. The three different files(DAT file, F90 file and BMP file) are encrypted and decrypted sequence simultaneously. The experiment is fulfilled and the high security is checked up.