By using a multi-hole-crucible and a furnace designed by ourselves

the CaF

2

crystals were grown by Bridgman-Stockbarger method under the vacuum condition. Under the growing condition of the vacuum below 3×10

-3

Pa

the axial gradient in growing zone about 1.8~2.5 ℃/mm

radial gradient below 0.5 ℃/mm

growing velocity of 3~4 mm/h and pre-annealing temperature descending velocity below 20 ℃/h

7 ingots of CaF

2

crystals with size of Φ57 mm×190 mm were grown in single process by melting

scavenging

homogenizing

controlling velocity and pre-annealing. The results show that the grown crystals with a wide transparent band have a good performance from 190 nm in ultra-violet to 9 000 nm in infra-red. The transmissivity is about 81% at 190 nm and 83% at 9 000 nm. The rate of mono-crystal is about 80%. The dislocation is about 30/mm

2

. The proposed equipment and technology are suited to batch production of CaF

2

crystals.