  The floating zone technique is a well-established single crystal growth
method in materials research, able to produce volumetrically large specimens
with extremely high purities. However, traditional furnace designs have relied
on heating from high-powered bulb sources in combination with parabolic
mirrors, and hence are constrained to transparent growth chambers with large
solid angles of optical access. This results in a stark limitation on
achievable processing gas pressures, and in turn renders a range of compounds
unsuitable for crystal growth by the floating zone technique, either due to
excessive volatility or due to metastability. Here, we demonstrate a novel
high-pressure laser-based floating zone system (HP-LFZ). The use of lasers for
heating allows implementation of a high-strength metal growth chamber,
permitting greatly enhanced processing pressures over conventional mirror-based
designs, with the current design allowing for pressures up to 1000 bar. We
demonstrate a series of example single crystal growths using this design in
pressures up to 675 bar, a significant increase over processing pressures
attainable in commercially available floating zone systems. The general utility
of the HP-LFZ is also illustrated via growths of a range of complex oxides.
