Large volume oriented single crystals with a homogeneous refractive index and low stress related birefringence

摘要

Device for growing large volume single crystals comprises a housing (10) in which a melt crucible (20) with side walls (22), a base (24), a top opening (26) facing the base and optionally a lid (28) are located; and at least one heating element (50, 50'). At least one heating element is arranged on the side walls of the melt crucible (20) to prevent lateral radial heat flow. An independent claim is also included for a process for growing large volume single crystals using the above device. Preferred Features: The elements arranged on the side walls prevent lateral heat flow so that a planar solid/liquid phase boundary surface is formed during crystal growth which has a bending radius of at least 1 m. The base of the crucible has a conical shape.