Intermittency and chaos in intracavity doubled lasers. II

Abstract

We describe the nonlinear dynamics of intracavity doubled multimode lasers. Baer [J. Opt. Soc. Am. B 3, 1175Am. B 3, (1986] observed irregular amplitude fluctuations in a multimode yttrium aluminum garnet laser with an intracavity potassium titanyl phosphate frequency-doubling crystal; we identify type-III intermittency as the route to chaos. Subsequently, Oka and Kubota [Opt. Lett. 13, 805 (1988)] demonstrated the stabilization of such a laser by the introduction of a quarter wave plate into the cavity. A generalized model of rate equations for this case is introduced. It is shown that a second route to chaos through a Hopf bifurcation, synchronization, and period-doubling sequence occurs on rotation of the quarter wave plate within the cavity. In addition, we predict that the laser output may be stable for particular lengths of the doubling crystal.

Peculiarities of mode competition in a double-mode diode-pumped Nd:YAG laser

“…Data about values γ, γ a , γ b [14] and our estimate of the cavity bandwidth of the laser show that the inequality (5) is reasonable. The fact that the relaxation of the population of the upper working level is slow as compared with variations in the laser field intensity results in the appearance of the integral addends in Eq.…”

Numerical study of reverse period doubling route from chaos to stability in a two-mode intracavity doubled Nd-YAG laser

“…It is found to be stable for higher values of g. It was analytically showed that when gϭ1 there was no sum frequency generation and hence there was no nonlinear coupling between the different modes so that the output intensity was stable. 18 Figure 2 shows the phase portraits for the laser. Here the total infrared intensity is plotted against total gain for different values of g. The phase portrait shows a complex behavior in the chaotic region as shown in Fig.…”

“…12 In a series of papers Roy et al showed that the fluctuations in intensity are manifestations of deterministic chaos in the system. [13][14][15][16][17][18] The instability of laser system with nonlinear mode-mode coupling was predicted by Arecchi and Ricca.…”

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

“…We assumed that the laser is operating with three coexisting longitudinal modes, with two modes polarized parallel to each other and the third mode polarized orthogonal. The case was experimentally studied by James and Harrel [15]. They found that the chaotic amplitude fluctuations in the system can be eliminated by proper rotary alignment of the angle between the fast axes of the Nd:YAG and KTP crystals.…”

“…In this paper we report the results of our numerical studies on the effect of coupling of two multimode Nd:YAG lasers with intracavity KTP crystal for frequency doubling. The chaotic behavior of such a laser has been studied extensively by many authors both experimentally and theoretically [14][15][16][17][18][19][20][21][22].…”