• Crystal Growth
• Laser
• Optics
• Quantum Information
• Rare Earth Ions doped Materials

In this thesis, crystal growth of fluoride materials using Czochralski (CZ) and micro pulling down technique as well as its applications in optical field will be introduced in detail.
Bulk crystals of 5%, 7.5% and 10% Yb3+ doped LiYF4 crystals were successfully grown using Cz method for optical refrigeration application. Although behavior of these crystals in optical refrigeration was not very attractive, spectroscopic analysis of influence from impurities inside the crystals provide interesting and useful information of energy transfer between ytterbium, holmium, erbium and thulium, which could be meaningful for future development of ytterbium doped crystal for optical refrigeration application.
Bulk crystals of 0.02% Er3+ doped KYF4 and 0.1% Eu3+ doped KYF4 were also successfully grown using CZ technique for quantum information application. Both of the zero phonon transitions between 4I13/2 and 4I15/2 manifolds in Er3+ and the zero phonon transitions between 7F0 and 5D0 manifolds in Eu3+ in KYF4 exhibit a multiline structure, corresponding to six individual sites for rare earth dopants in the host. High resolution spectroscopic measurement was performed on the europium doped KYF4 crystal at two of the six europium ions sites.Photon echoes experiments were performed and for the first time photon echoes were performed on a europium doped fluoride material. Homogeneous linewidths of these two sites at 1.8 K were determined to be 20.1 kHz and 17.5 kHz respectively, corresponding with a coherence lifetime of tens of microseconds.
Besides bulk crystals, fiber shaped crystals were also grown employing micro-PD process, mainly for laser applications. 1% Pr3+ doped LiLuF4, YLF, KY3F10 and Ho3+ doped YLF crystal fibers have been successfully grown my micro-PD method. Visible laser output has been successfully performed employing one sample of Pr: LLF fiber. The result of laser experiment suggested the crystal fibers grown by micro-PD technique could exhibit comparable optical quality with those obtained by CZ method.