On the use of laser induced breakdown spectroscopy to characterize the naturally existing crystal in Pakistan and its optical emission spectrum

We have used the Laser Induced Breakdown Spectroscopic (LIBS) technique to qualitatively identify the naturally existing transparent crystal as a pure quartz (SiO2) by observing its optical emission spectra using a Q-switched Nd:YAG laser, fundamental wavelength at 1064 nm and second harmonic at 532 nm. The spectra were registered using a set of five miniature spectrometers covering the spectral range from 200 nm to 720 nm. The plasma temperature has been calculated in the range from 8500 K to 10,200 K and the electron densities determined from the Stark broadened spectral lines in the range of 1.0 × 1017 cm− 3 to 6.0 × 1017 cm− 3. We report here the full widths at maximum of the spectral lines associated with the 3p4s 3P0,1,2 → 3p23P0,1,2, 1S0, 1D2 transitions in Si and four multiplets of singly ionized silicon.