ABSTRACT
Self-induced pulsations that are associated with atomic interference have been found in a laser-diode-pumped LiNdP(4)O(12) microchip laser with an intracavity KTP frequency-doubling crystal operating in a ? scheme. The instability and peculiar pulsations that were observed have been verified by a linear stability analysis and numerical simulation of two-mode laser equations, including nonlinear absorptions of a purely quantum nature and spontaneous-emission noise.
ABSTRACT
Dynamical instability, chaotic pulsations, and generalized bistability have been observed in a laser-diode-pumped microchip Nd:YAG laser operating in a double transition scheme in which lasing occurs on two transitions with overlapping gain profiles, F(3/2)(4)(2)? I(11/2)(4)(3) and F(3/2)(4)(1)? I(11/2)(4)(2), and simultaneously involves excited Nd atoms from different sublevels of the upper manifold. The modeling of the experimental results requires rate equations that include cross-gain coupling among oscillating modes that belong to different transitions whose population inversion densities are determined by the Boltzmann distribution.
ABSTRACT
1.5-mum emissions from Nd:YAG, Nd:YVO(4), and LiNdP(4) O>(12) microchip lasers pumped by laser diodes have been observed. These coherent emissions are attributed to the effect of high-energy modified lattice vibration owing to the existence of Nd ions as well as to stimulated intracavity Raman scattering enhanced by the microchip configuration. A four-wave mixing process involving two lasing fields and a Stokes field was identified as the generator of new adjacent 1.5-mu;m emission.
ABSTRACT
Suppressing chaotic behavior by addition of a weak second periodic perturbation signal, which is nearly resonant to a subharmonic of the fundamental system frequency, is observed in a modulated microchip LiNdP(4)O(12) multimode laser by a highly sensitive self-mixing modulation technique. The stabilization of the unstable period-2 orbit embedded in a chaotic attractor is demonstrated in a wide parameter region. The chaos-suppressing experiments are well reproduced by simulations of globally coupled modulated Tang-Statz-deMars [J. Appl. Phys. 34 8289 (1963)] multimode laser equations, including a spatial hole-burning effect.
ABSTRACT
A novel method for producing high-speed picosecond optical pulses from semiconductor laser diodes that uses incoherent optical feedback is proposed. The incoherent optical feedback provides a successive pulselike modulation in carrier density and drives the system to a self-sustained pulsation state whose repetition rate is determined by relaxation oscillations.
ABSTRACT
We consider an optical ring cavity with four nonlinear elements and investigate its all-optical flip-flop operation and the types of switching between its multiple stable states. All-optical flip-flop operation is shown to exist, and the possible switching modes are determined. We also discuss the difference between the slowly varying input and pulse-injection processes. Moreover a procedure to obtain the preinjection states that are needed for operation is proposed.
