Abstract: There is described a method for identifying at least one target in a substantially transparent medium. High-power, ultra-short laser pulses are transmitted into the medium. A diameter of the laser pulses is enlarged and the laser pulses having an enlarged beam diameter are focused using a focusing element so as to generate filaments substantially near a geometrical focal zone of the focusing element, whereby a spontaneous fluorescence signal (amplified through amplified spontaneous emission or not) is detected and analyzed to identify the target.

Abstract: Methods and devices for generating stable, tunable and intense output light pulses are provided. A primary beam of light pulses is used to form a filament in an interaction zone. A secondary bean of light pulses is superposed with the filament and interacts therewith to generate the output light pulses. The parameters of the primary and secondary beams in the interaction zone can be controlled to obtain targeted optical characteristics of the output pulses. Multiple secondary beams may also be used.

Abstract: Methods and devices for generating stable, tunable and intense output light pulses are provided. A primary beam of light pulses is used to form a filament in an interaction zone. A secondary bean of light pulses is superposed with the filament and interacts therewith to generate the output light pulses. The parameters of the primary and secondary beams in the interaction zone can be controlled to obtain targeted optical characteristics of the output pulses. Multiple secondary beaus may also be used.

Abstract: There is described a method for identifying at least one molecule in a substantially transparent medium, the method comprising: transmitting high-power, ultra-short laser pulses into the medium so as to generate filaments in which a spontaneous fluorescence signal propagating along an axis of the filament is amplified by stimulated emission; detecting the amplified spontaneous fluorescence signal; and analyzing the florescence signal to identify said molecule.

Abstract: There is described a method for identifying at least one molecule in a substantially transparent medium, the method comprising: transmitting high-power, ultra-short laser pulses into the medium so as to generate filaments in which a spontaneous fluorescence signal propagating along an axis of the filament is amplified by stimulated emission; detecting the amplified spontaneous fluorescence signal; and analyzing the florescence signal to identify said molecule.

Abstract: A method of processing lignocellulosic material comprises the steps of (a) generating a pulsed laser beam consisting of a train of laser pulses, each laser pulse having a duration less than 1.times.10.sup.-9 sec. and a peak intensity of at least 1.times.10.sup.11 w/cm.sup.2 ; and (b) directing the laser beam generated in step (a) onto a surface of the lignocellulosic material to cause ionization and fragmentation of macro-molecules thereof. The method of the invention enables one to cut, carve and/or sand the surface of lignocellulosic material without, burning same or damaging the cells of the lignocellulosic material.