The effect of air flow on the temperature distribution and the harmonic conversion efficiency of the ADP crystal with large aperture in the temperature control scheme

•A temperature control scheme is proposed.•The influence of the air flow in the cavity and the ambient air flow are studied.•The effect of air flow in the cavity in the heating process is discussed.•The relationship of the crystal temperature and ambient temperature is obtained.

This paper presented a temperature control scheme for ammonium dihydrogen phosphate (ADP) crystal of Ф80 mm in diameter, and the influence of the air flow was also studied. This research aims to obtain the high energy, high frequency laser with large aperture under the non-critical phase matching (NCPM). Firstly, thermal analysis was carried out to investigate the air flow property in the cavity, as well as the effect of ambient temperature was analyzed. Secondly, the temperature distributions of air flow were achieved using the Finite Volume Method (FVM), and this prediction was validated by the experiment results. Finally, the effect of air flow in the cavity was obtained from the heating method, and the variation of harmonic conversion efficiency caused by the ambient temperature was also highlighted.