0000000000194771
AUTHOR
J. L. Font
Transverse effects in a thin slab of material with local-field induced intrinsic optical bistability
We consider a thin slab of dense material exhibiting local-field induced intrinsic optical bistability irradiated by a transversely uniform optical field (holding beam). We study the transverse effects that can arise when local excitations are created by means of a narrow optical beam (writing beam). We show that whereas diffraction effects are negligible, diffusion effects make the excitation-domain walls to move inward or outward in the transverse direction, with a speed that depends on the holding-beam intensity and the diffusion coefficient. Conditions can be found, however, for which the wall movement is counterbalanced by the field transverse gradient so that stable narrow excitation …
Steady-state emission and stability of a single-mode two-level Fabry-Perot cavity laser
Abstract An analytical steady-state solution for a single-mode homogeneously-broadened two-level Fabry-Perot laser, valid for any field intensity, cavity detuning and level-population decay rates, is obtained. A power-series expansion of this solution allows to perform a linear stability analysis which reveals the existence of two Hopf bifurcations instead of one as in unidirectional ring lasers. These bifurcations delimit the domain of unstable emission of the laser with respect to small perturbations. The instability threshold for hard-mode excitation is higher than in a ring laser, although introduction of a small definite detuning makes them similar. The time-dependent behaviour above t…
Addressing optical pixel bits in a slab of dense optical material via intrinsic optical bistability
It is well known that dense materials with local-field effects can show "intrinsic" optical bistability when they are directly irradiated by a light beam. This has been shown theoretically in a number of works and also experimentally in several cases, in gas media and also in doped solid-state materials where nonlinearities based on standard local-field effects can be reinforced with other ion interaction effects. Although from the point of view of applications nonlinearities stronger than those found so far would be desirable, the fact that no optical resonator is needed to achieve bistability makes these materials potentially interesting for applications in optical information storage and…
Coexistence of single-mode and multi-longitudinal mode emission in the ring laser model
A homogeneously broadened unidirectonal ring laser can emit in several longitudinal modes for large enough pump and cavity length because of Rabi splitting induced gain. This is the so called Risken-Nummedal-Graham-Haken (RNGH) instability. We investigate numerically the properties of the multi-mode solution. We show that this solution can coexist with the single-mode one, and its stability domain can extend to pump values smaller than the critical pump of the RNGH instability. Morevoer, we show that the multi-mode solution for large pump values is affected by two different instabilities: a pitchfork bifurcation, which preserves phase-locking, and a Hopf bifurcation, which destroys it.