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Stimulated Raman scattering (SRS) of OH stretching vibrations in pure water and dilute ethanol–water solutions under different pump laser energies has been investigated using Nd:YAG laser. Two characteristic peaks at about 3252 and 3390 cm−1 are observed in mixture solutions, indicating the formation of strong and weak hydrogen bonds in water. A new shoulder peak at 3350 cm−1 appears in the mixture solutions at high laser energy due to the enhancement of hydrogen bond structure of water molecules. Simultaneously, the normalized SRS intensity of mixture solutions is higher than that of pure water at the same laser energy. These results indicate that SRS of water molecules is enhanced in dilute ethanol–water solutions. We propose that the mechanism is the reduction of the laser breakdown threshold of liquid water via ethanol, resulting in a strong nanoshock wave, thereby enhancing the SRS of water. [ABSTRACT FROM AUTHOR]

Forward stimulated Raman scattering in pure water and H2O2–H2O mixture solutions are investigated under different pump laser energies. Three characteristic peaks are observed in mixture solutions due to the enhancement of hydrogen bonds (H‐bonds) structure of water molecules by H2O2. Simultaneously, stimulated Raman scattering lines indicate that high‐pressure ice‐phase is formed in mixture solutions, which is attributed to the reduction of the laser breakdown threshold of liquid water by H2O2, resulting in a strong dynamic high pressure. [ABSTRACT FROM AUTHOR]

Stimulated Raman scattering (SRS) in H2O2–H2O mixture solutions are obtained in forward and backward directions. Characteristic features peaks related to OH stretching vibrations of water are the appearance of three enhancement peaks in both directions. Simultaneously, the low‐wavenumber SRS peaks in water at 840 and 1,700 cm−1 are enhanced. The mechanism of enhancement is attributed to excess electron‐enhanced Raman scattering. The electron‐enhanced process is also discussed. [ABSTRACT FROM AUTHOR]

Stimulated Raman scattering (SRS) of liquid water and heavy water have been investigated using Nd:YAG laser. The SRS spectra of liquid heavy water indicate that ice–VII and ice–VIII structures are formed by shock-induced compression (SIC) in forward and backward directions, respectively. Simultaneously, the SRS spectra reveal of liquid water that only ice-VII structure is formed in the backward direction. The difference in ice structures formed by SIC in liquid water and heavy water could be attributed to the effect of the hydrogen bond quantum nature with H + . SRS spectra of 2 M NaOH water solution with ice–VII and ice-VIII structures have been successfully obtained in forward and backward, respectively, as OH − greatly reduce the quantum nature of hydrogen bonds by neutralizing H + in water. The hydrogen bond quantum nature is important for understanding isotope calibration test structure and isotopic effect. [ABSTRACT FROM AUTHOR]