Practice of Micro Pulling Down Growth

In this chapter we will focus on practical aspects of the micro pulling down growth method. Basic prerequisites for successful use of monocrystalline optical fibers are that they have to be grown with specific and homogeneous composition and smooth cylindrical geometry. In the first part of the chapter the problems of longitudinal homogeneity and surface quality of μ-PD fibers are addressed in detail. Direct implementation of these considerations is that significant improvement of fiber quality can be achieved only under precise control of the meniscus height. In the second part of the chapter the reverse situation is discussed: the intentional use of growth parameter variations during μ-PD for different growth studies. Here μ-PD appears as supporting instrumentality for bulk melt growth technologies. Because of the excellent stability and simplicity, the method has been proven to be a very useful research tool.