Terahertz Wave Generation from Water at Different Temperatures

We experimentally measure the temperature dependence of terahertz generation from a liquid water line excited by sub-picosecond laser pulses. To study the effect of water density change on THz wave emission, the water temperature range is set from 3.5 to 90 °C, with a smaller step between 3.5 and 5.5 °C due to the maximum density of liquid water at 4.0 °C. Moreover, the relationship between water flow rate and temperature is investigated. The result shows the measured change of emitted THz field vs the variation of water temperature.