Crystal growing device with multiple heat generating units and method

The invention relates to a method and device for growing fluoride crystals under vacuum conditions by adopting a Bridgman method. A hot area of the device consists of three independent heat generating units, and each heat generating unit comprises a thermocouple, a single-phase power regulator, a temperature controller and the like. The three heat generating units simultaneously work, are subjected to independent temperature control and jointly form a heat generating zone in a crystal growing furnace. Through separately setting temperatures of the three heat generating units, a temperature gradient, ascending along the axial direction of a crucible, can be established in crystal melt. The temperature field structure is beneficial to the avoidance of convection of the melt in the crucible and the reduction of axle aggregation of bubbles and impurities inside the crystals. A cold area of the device adopts a graphite heat insulation tube, so that the asymmetry of an axial temperature field caused by existence of electrodes in a temperature field of the cold area can be prevented, the uniformity and axial rotation symmetry of a temperature field at a solid-fluid interface can be effectively guaranteed, and the obtaining of a smooth solid-fluid interface is facilitated. Therefore, grown crystals have relatively small internal stress and relatively low stress birefringence, and the quality of the crystals is improved.