Dynamics of two coupled chaotic multimode Nd:YAG lasers with intracavity frequency doubling crystal

Abstract

Abstract. The effect of coupling two chaotic Nd:YAG lasers with intracavity KTP crystal for frequency doubling is numerically studied for the case of the laser operating in three longitudinal modes. It is seen that the system goes from chaotic to periodic and then to steady state as the coupling constant is increased. The intensity time series and phase diagrams are drawn and the Lyapunov characteristic exponent is calculated to characterize the chaotic and periodic regions.

Bidirectional communication using delay coupled chaotic directly modulated semiconductor lasers

“…view in secure communication [27][28][29][30][31][32][33][34][35][36][37][38]. However, the mode gain reduction occurring in such systems due to nonlinear processes suppresses chaotic dynamics [27].…”

“…Chaotic synchronization of two such lasers with low values of nonlinear gain reduction factor is achieved and successfully applied for unidirectional optical secure communication [30,31]. A bidirectional coupling of two such lasers is also found to suppress chaotic dynamics [32]. It is recently reported that a negative-delayed optoelectronic feedback is capable of producing chaotic outputs from directly modulated semiconductor lasers with optimum value of nonlinear gain suppression factor [33].…”

Synchronization and control of chaos in coupled chaotic multimode Nd:YAG lasers

“…Two such lasers are coupled via external electronic coupling [2] whereby the pumping of each laser is modulated according to the output intensity of the other. The rate equations for the coupled system are given by …”

“…This phenomenon has found many applications in laser dynamics [1][2][3][4], electronic circuits [5,6], chemical and biological systems [7,8] and secure communication [9,10]. Dynamics of an array of coupled systems has also been studied for coupled maps [11][12][13], coupled semi conductor lasers [14], neural networks [15] and in the Josephson junction [16].…”

“…They have also studied the chaotic behavior of two coupled single mode Nd:YAG lasers [19]. Coupled dynamics of two chaotic Nd:YAG lasers operating in three longitudinal modes were studied to show that the system goes from chaotic state to periodic and then to steady state as the coupling strength is increased [2].…”