Floating zone furnace equipped with a high power laser of 1kW composed of five smart beams

TL;DR

This paper introduces a novel floating zone furnace equipped with a 1kW diode laser composed of five beams, enabling precise control and monitoring of high-temperature crystal growth for refractory and volatile materials.

Contribution

The paper presents a new high-power laser-based floating zone furnace with multi-beam irradiation and in-situ temperature monitoring capabilities for advanced crystal growth.

Findings

Enables growth of refractory and volatile materials above 2000°C

Provides uniform and bell-shaped irradiation intensity

Allows direct temperature monitoring of the molten zone

Abstract

A floating zone furnace is a powerful tool for single crystal growth. Here, we report the floating zone furnace using a high power diode laser of 1kW composed of five 200 Watt heating beams. The five beams with the designed irradiation intensity distribution enable the melt-growth of single crystals for refractory materials having a high melting temperature above 2000{\deg}C, volatile materials and even incongruent materials. The power of five beams in the horizontal plane provides uniform intensity in the outer circumference of the raw material rods, while the vertical direction power of five beams can be made to have a bell shape irradiation intensity so as to relax residual thermal stress in the grown single crystal. The present furnace enables one to directly monitor the temperature of the hot spot of raw material and the molten zone within a 1 mm diameter. Such an in-situ monitoring function of the temperature on the molten zone greatly enhances the controllability for optimizing the crystal growth condition.