Proceedings PaperUltrashort Laser Pulse Generation And Applications
|Format||Member Price||Non-Member Price|
Some recent results in the field of femotosecond laser pulse generation are reviewed, including the generation of 6 fsec duration pulses and its applications to time resolved spectroscopic studies in condensed matter. In this paper we review some recent results in the field of femtosecond duration laser pulse generation, together with some applications to the study of dynamic processes in ma-terials. a) Generation of 6 femtosecond laser pulses Pulses as short as 6 femtoseconds can be generated today through the use of a pulse compression scheme that is able to compensate the phase distortions of the propagating pulses up to third order 1 This system works with pulses generated in a colliding pulse mode locked dye laser 2 emmiting 50 fsec pulses which are amplified to an energy of a few microjoules in a copper vapor laser pumped multipass amplifier 3 . A fraction of the amplified pulses is coupled into a small length (9 mm) of monomode optical fiber which has a core diameter of 4 micrometers. Due to the process of self phase modulation the spectral width of the pulse emerging from the fiber is much larger than that of the input pulse. This pulse can then be compressed through the use of a suitable dispersive delay line which corrects the phase distortions accumulated by the pulse upon propagation in the fiber. This delay line is made up of a combination of a pair of diffraction gratings and a pair of prisms, in such a way that by a careful adjustment of the prism and grating separation it is possible to correct the phase distortions in the pulse up to third order.