Optical pattern formation with a two-level nonlinearity
نویسندگان
چکیده
We present an experimental and theoretical investigation of spontaneous pattern formation in the transverse section of a single retroreflected laser beam passing through a cloud of cold rubidium atoms. In contrast to previously investigated systems, the nonlinearity at work here is that of a two-level atom, which realizes the paradigmatic situation considered in many theoretical studies of optical pattern formation. In particular, we are able to observe the disappearance of the patterns at high intensity due to the intrinsic saturable character of two-level atomic transitions.
منابع مشابه
Dispersion and Nonlinearity in Ultra-Optical Ga2O3 and TiO2-Bi2O3-PbO Glass Systems
Dispersion, as the characteristic variation of refractive index with wavelength, is more pronounced, where the wavelength is approaching to the absorption band. In ultra-optical glasses, the nonlinear refractive index, concerning to the light intensity dependent phenomenon, becomes considerable. Here, two ultra-optical property glass systems; TiO2-Bi2O3-PbO (TBP...
متن کاملSelection of Unstable Patterns and Control of Optical Turbulence by Fourier Plane Filtering
We report on selection and stabilization of transverse optical patterns in a feedback mirror experiment. Amplitude filtering in the Fourier plane is used to select otherwise unstable spatial patterns. Optical turbulence observed for nonlinearities far above the pattern formation threshold is stabilized by low-pass filtering of the optical power spectrum. Experimental observations obtained with ...
متن کاملSPATIAL PATTERNS IN NONLINEAR OPTICS Pattern Formation in Optical Cavities With Incoherent Light
terns of this non-resonant system exhibit spatial line narrowing with the increase of feedback, resembling the line narrowing in (resonant) lasers (see Fig. 1). In fact, despite the incoherence of the light, this cavity threshold is analogous to many thresholds in resonant feedback systems with gain.1 In a subsequent paper, we theoretically analyzed a cavity in which the light was also spatiall...
متن کاملUltrashort Pulse Lossless Propagation Through a Degenerate Three-Level Medium in Nonlinear Optical Waveguides and Semiconductor Microcavities
The authors develop and apply a novel group-theoretical approach for studying the coherent dynamics of ultrashort pulse propagation in nonlinear optical waveguides and passive semiconductor microresonators. The resonant nonlinearity is modeled by a degenerate three-level system of saturable absorbers in order to allow for a two-dimensional medium polarization. The resulting Maxwell-pseudospin e...
متن کاملSpontaneous spatial fractal pattern formation in absorptive systems
We predict, for the first time to our knowledge, that purely-absorptive nonlinearity can support spontaneous spatial fractal pattern formation. A passive optical ring cavity with a thin slice of saturable absorber is analyzed. Linear stability analysis yields threshold curves for Turing (static) instabilities with features proposed as characteristics of potential fractal pattern formation. Nume...
متن کامل