Flashlamp-pumped Nd:YAG laser with higher pulse energy using TiO2 nanofluid as coolant

In this study, water-based nanofluid containing titanium oxide nanoparticles with Rutile phase was employed to improve the efficiency of a typical flashlamp-pumped Nd:YAG laser. The pulse energy has been raised up to 86 mJ or about 12% in comparison with pure deionized water. Theoretical approach showed that the heat transfer coefficient of TiO2 based nanofluid is higher than pure deionized water (about 14%) which increases the laser efficiency due to the better heat removal from the gain media. To evaluate the effects of nanofluid utilization on the pump source efficiency, for the first time, a semi-analytical expression has been derived. Based on the noted semi-analytical expression, calculations showed that the photoluminescence of the TiO2 nanofluid is mainly canceled by its absorption within the useful pump band of the gain media so that the pump source efficiency actually drops when the nanofluid is used.