SearcharxivSearch

arXiv subjects

Amrutha Gopal

Publications and source records attributed to Amrutha Gopal.

3 recordsLinked to original sources

Energy deposition dynamics of femtosecond pulses in water

We exploit inverse Raman scattering and solvated electron absorption to perform a quantitative characterization of the energy loss and ionization dynamics in water with tightly focused near-infrared femtosecond pulses. A comparison between experimental data and numerical simulations suggests that the ionization energy of water is 8 eV, rather than the commonly used value of 6.5 eV. We also introduce an equation for the Raman gain valid for ultra-short pulses that validates our experimental procedure.

physics.optics

Time-resolved refractive index and absorption mapping of light-plasma filaments in water

By means of a quantitative shadowgraphic method, we performed a space-time characterization of the refractive index variation and transient absorption induced by a light-plasma filament generated by a 100 fs laser pulse in water. The formation and evolution of the plasma channel in the proximity of the nonlinear focus were observed with a 23 fs time resolution.

physics.optics

Quantitative two-dimensional shadowgraphic set-up for high-sensitivity measurement of low-density laser-plasmas

We present a quantitative shadowgraphic method which can measure the density of a laser-generated plasma in air with sensitivity and resolution comparable or better than traditional interferometric techniques. Simultaneous comparison of both shadowgraphy and interferometry has been carried out allowing the experimental evaluation of the reliability of the shadowgraphic method.

physics.optics