Observation of an icelike state in supercooled water and its destruction by laser pulses

An icelike state of water supercooled to ?1°C was found using Raman spectra excited by second harmonic pulses from a Nd:YAG laser. The spectrum of the OH stretching vibrations of this state was found to be similar to the spectrum of hexagonal (Ih) ice. The icelike state is destroyed by laser pulses of a moderate intensity (1 MW/cm²) with a repetition frequency of 1 Hz, and the water returns to its initial state, with no icelike clusters, within five minutes through an aperiodic process of variation in the concentration of hydrogen bonds without changing its macroscopic temperature.