TIME RESOLVED IMAGING SPECTROSCOPY APPLIED TO THE ANALYSIS OF PLASMAS GENERATED BY MICRO, NANO AND FEMTOSECOND LASERS

F. C. ALVIRA; L. PONCE; M. ARRONTE; G. M. BILMES

Lima, Peru

Congreso; VIII Reunion Iberoamericana de Optica X Encuentro latinoamericano de optica, laseres y aplicacions; 2010

Pontificia Universidad Catolica del peru

The spatial and temporal evolution of laser-generated plasmas are of interest not only for the study of plasma physics itself, but because it improves the application of techniques, such as LIBS, (Laser-Induced Breakdown Spectroscopy), that use the emission of these plasmas for the characterization of materials, products and processes.  Time resolved hyperspectral spectroscopy is a tool for the study of these plasmas. Its implementation requires the use of spectrometers with both spectral and spatial resolution (imaging spectrometers), and time resolved detection. With the aim to identify the best space-time conditions that optimize the spectral information obtained in LIBS, in this paper we have applied time resolved hyperspectral spectroscopy to the study of plasmas generated in copper and aluminium by lasers with pulses of different duration. Lasers with microsecond, nanosecond and femtosecond pulses as well as multipulse emission were used. We recorded the spatial and temporal distribution of the intensity of the main emission lines of atoms and ions of each species, as a function of the laser pulse duration. With these data we have determined plasma electron densities as a function of the laser pulse duration. Results show that the spatial and temporal evolution of the intensity of the main emission lines of each species depends on the excitation pulse duration.