Publisher’s Note: “Estimating the pressure of laser-induced plasma shockwave by stimulated Raman shift of lattice translational modes” [Appl. Phys. Lett. 101, 021908 (2012)]

Onset of ice VII phase of liquid water: role of filamentation in stimulated Raman scattering

“…In addition to filamentation, laserinduced plasma launches a shock wave in the medium because of high pressure and temperature gradients leading to phase transitions of stable molecules [4][5][6][7][8][9][10]. In this Letter, we present (a) the onset of ice VII phase of liquid water detected by a forward SRS signal, and (b) the role of filamentation in SRS, during propagation of a 30 ps pulse through liquid water.Typically, ns laser pulses were employed to create high pressures leading to phase transformations detected by SRS signals in both forward and backward directions [3][4][5][6]9,10]. Recently, the phase transformation of liquid water to ice VII and ice X because of a high shock pressure of 62 GPa generated at the focal volume using high energy nanosecond (12 ns, 532 nm, 360 mJ) laser produced plasma (LPP) is reported [4].…”

“…Recently, the phase transformation of liquid water to ice VII and ice X because of a high shock pressure of 62 GPa generated at the focal volume using high energy nanosecond (12 ns, 532 nm, 360 mJ) laser produced plasma (LPP) is reported [4]. The high pressure phases of liquid water such as ice VII, protonated ice VIII, and cuprite ice X were identified with the help of an SRS signal during nanosecond laser pulse excitation [3][4][5]9,10] which have established SRS as an essential tool to estimate the pressure in the medium during phase transitions. Though several studies reported the formation of dynamic states of water excited by ns laser pulses [3][4][5] observation of phase transitions because of optical breakdown using ps [6] and fs pulses, which invoke self-action effects such as filamentation [12][13][14], is sparse.…”

“…Typically, ns laser pulses were employed to create high pressures leading to phase transformations detected by SRS signals in both forward and backward directions [3][4][5][6]9,10]. Recently, the phase transformation of liquid water to ice VII and ice X because of a high shock pressure of 62 GPa generated at the focal volume using high energy nanosecond (12 ns, 532 nm, 360 mJ) laser produced plasma (LPP) is reported [4].…”

“…The dynamical balance between the laser generated plasma and the self-focusing, known as filamentation, channelizes the laser energy along the propagation direction [12]. In addition to filamentation, laserinduced plasma launches a shock wave in the medium because of high pressure and temperature gradients leading to phase transitions of stable molecules [4][5][6][7][8][9][10]. In this Letter, we present (a) the onset of ice VII phase of liquid water detected by a forward SRS signal, and (b) the role of filamentation in SRS, during propagation of a 30 ps pulse through liquid water.…”

“…SRS has become an essential tool to study the laser-induced instantaneous nonlinear electronic polarizabilities [1-3] and molecular dynamics that lead to the appearance of novel phases of a stable molecule under both static or dynamic pressure and temperature gradients [4][5][6][7][8][9][10]. These phase transformations are manifested as SRS signals, with a specific Raman shift confirming the presence of a new phase of the material [3,4,[7][8][9]11]. SRS is also known to be amplified by self-focusing [1] which leads to higher intensities that ionize the medium generating plasma because of multi-photon processes.…”