Laser heated floated zone

Laser-heated float zone technique (reproduced by permission of Chapman Hall)56. 

Figure 6.12 Schematic of the laser-heated float zone technique of making ceramic fibers.

T. Kotani, J.K. Chen, H.L. Tuller, The Dopant Distribution in Ti-, Zr- and Cr-doped Y3AI5O12 Fibers Grown by the Laser Heated Floating Zone Method. J. Electroceramics, 2, 7-20 (1998)... 

Continuous single crystal fibers can be grown from inviscid melts by two relatively slow processes the edge defined film fed growth (EFG) process [13] and the laser heated float zone (LHFZ) or laser heated pedestal growth (LHPG) process [14]. Both offer growth rates of toO.3-0.7 mm/s [13-14]. 

In the laser heated float zone (LHFZ) or pedestal (LHPG) growth process, a circumferential laser is placed around a preform rod (e.g. polycrystalline alumina) to zone refine a segment of the material while at the same time updrawing a single crystal fiber (e.g., sapphire). 

Figure 17. Laser heated float zone or pedestal growth process (schematic drawing). Redrawn from R. S. Feigelson, Growth of fiber crystais, in Crystal growth of etedronic materials, E. Kaddis, pages 127-145, Elsevier Science Publishers, London (1985).

Three processes are known to fabricate continuous yttrium aluminum garnet (YAG) fibers. Single crystal YAG fibers are obtained by the edge defined film fed growth process and by the laser heated float zone process (Chapter 4.5). Both are slow processes. Amorphous YAG glass fibers have recently been demonstrated by a containerless laser heated melt process (Chapter 4.4). Polycrystalllne YAG fibers can be obtained with sol-gel and related processes (this chapter). These are potentially fast processes. 

K Takagi, M Ishii. Growth of LaBg single crystals by a laser heated floating zone method. J Cryst Growth 40 1, 1977. 

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