Showing papers on "Supercontinuum published in 1990"
TL;DR: The supercontinuum generated in H2O or D2O is a surface phenomenon whose origin is at the surface of self-trapped filaments and has optical properties characteristics of Cerenkov-type processes.
Abstract: Experimental evidence is presented that the supercontinuum generated in H2O or D2O is a surface phenomenon whose origin is at the surface of self-trapped filaments This is done by a comparison of the output patterns produced by spherical and cylindrical focusing lenses as well as comparison of the polarization of the incident and emitted light The similarity between the rings emitted during the supercontinuum generation, the conical emission generated in alkali metal vapors, and class II Raman radiation in liquids is pointed out Thus the supercontinuum has optical properties characteristics of Cerenkov-type processes
86 citations
TL;DR: Supercontinuum generation at 248 nm has been observed, for the first time to the authors' knowledge, by focusing subpicosecond laser pulses into neon, argon, and krypton gases at pressures as high as 40 atm.
Abstract: Supercontinuum generation at 248 nm has been observed, for the first time to the authors' knowledge, by focusing subpicosecond laser pulses into neon, argon, and krypton gases at pressures as high as 40 atm. In the case of neon, the continuum spans a wavelength range reaching from the visible to well into the vacuum ultraviolet. In the range of 200 to 300 nm, the continuum obtained by using krypton is of particularly high quality and therefore well suited to applications in ultrafast spectroscopy in this wavelength range.
23 citations
TL;DR: In this article, the possibility and advantages of a piezoelectrically tuned etalon for selection of a narrow line in a sub-picosecond supercontinuum was demonstrated.
5 citations
TL;DR: In this article, a theoretical model of emission from an atom excited by a strong laser field is proposed, where the main ideas incorporated in the model are: (i) time-dependent AC Stark shift of Rydberg levels; (ii) field-induced level crossing providing efficient resonance coherent population of rydberg level; (iii) fieldinduced interference suppression of photoionisation from rdberg levels in a strong field; and (iv) two-step transition from the zone of coherently excited Rdberg level to the ground level with spontaneous emission of a photon
Abstract: A theoretical model of emission from an atom excited by a strong laser field is proposed. The main ideas incorporated in the model are: (i) time-dependent AC Stark shift of Rydberg levels; (ii) field-induced level crossing providing efficient resonance coherent population of Rydberg levels; (iii) field-induced interference suppression of photoionisation from Rydberg levels in a strong field; (iv) two-step transition from the zone of coherently excited Rydberg levels to the ground level with spontaneous emission of a photon at the first step and stimulated emission of some laser photons at the second step. The model is shown to describe qualitatively the main features of the experimentally observed supercontinuum, i.e. a substantially broadened spectrum of emitted light.
4 citations