1 kW and 2 kW laser furnace for the production of long single crystalsfrom Quantum Design Japan
The 1 kW and 2 kW laser furnace for single crystal fabrication is based on a design and developed in close cooperation with the RIKEN Center for Emergent Matter Science under the leadership of Yoshio Kaneko. Both melting zones have 5 lasers each, which guarantees a high uniformity of power density in the melting zone range. The laser profile has been optimized to reduce thermal stress during the crystal growth process. In addition, the system includes an integrated temperature sensor for real-time temperature monitoring. Temperatures up to 3000 °C can be reached and thus also materials with a very high vapor pressure, a narrow temperature range of the melt, a high thermal conductivity coefficient and incongruent melts can be melted.Features
- Wide temperature range from 500 °C to 3000 °C
- Reduction of thermal stresses due to adapted laser profile
- Real-time temperature monitoring
- Suitable for degassing materials
- High laser stability due to patented design
Wide temperature range from low to high melting temperatures
It is possible to cover the entire temperature range with these laser furnaces, for which several furnaces with halogen and xenon lamps are usually required. 500 °C to 3000 °C can be achieved without the need for laser alignment or other optical system adjustments.
Laser beam profile
The irradiation intensity distribution of the heating laser is uniform in the circumferential direction. A gradual irradiation intensity distribution is produced in the direction of crystal growth. A circumferential homogeneity of more than 95% of the irradiation intensity on the outer surface of the raw material is achieved. This corresponds to excellent circumferential uniformity compared to a halogen melting zone furnace. This optimization of the laser beam profile reduces the thermal stress on crystals compared to conventional laser FZ furnaces, which typically consist of a step profile. This considerably reduces the probability of cracking due to thermal stresses.
The temperature can be monitored accurately and in real time.
Temperature monitoring has a point accuracy of better than 1.5 mm. The temperature of the melt zone can be directly monitored and recorded over the entire temperature range up to 3000 °C with an integrated radiation thermometer. This enables high-precision single crystal growth. High-precision temperature control of the desired melt zone temperature is possible. The temperature of the melt zone can be monitored in real time. This ensures growth at the desired temperature according to the phase diagram of the material. With other systems, there is no choice but to visually observe the fluctuating state of the melt zone, as accurate temperature measurement in the melt zone region is not possible. The crystal growing furnace is ideal for traveling solvent floating zone (TSFZ) crystal fabrication, which requires long-term, unattended temperature control over a narrow temperature range. The reproducibility of the measured temperature is within ±1°C. Once the optimum temperature is found, the laser power can be controlled to the desired temperature with excellent reproducibility.
Remote control of crystal growth
Observable and controllable crystal growth from the desk, at home and from any other remote location is only made possible by the excellent and reproducible temperature control. Direct observation of the temperature and melt pattern of the melt zone improves the reliability of the crystal growth process.
Ideal for materials with high volatility
Since the irradiation point is small, contamination of the inner surface of the quartz tube is low, and single crystal growth is possible even for materials with strong outgassing. It is possible to install a quartz tube protection sleeve for the evaporation materials, which simplifies the cleaning of the quartz tube after use. Only one cleaning of the protective sleeve is required.
Safe radiant heat stability
The use of the RIKEN optical system ensures radiation stability. The diode laser source (DL source) is divided into 5 laser beams. A stable optical system ensures that the 5 heating laser beams do not fluctuate. The power of each individual heating beam is the same for all 5 beams. The laser beam is a continuous oscillation laser. The irradiation intensity is very stable over time.
The temperature fluctuations of the heating laser are reduced by a simple cooling mechanism. Since only one DL is used, a cooling system is also sufficient to achieve a high temperature control accuracy.
Use of gas atmospheres
A single laser melting zone system can be configured for the use of oxygen atmosphere and for oxygen-free atmosphere.
- 5 laser beams generated by a high-power diode laser
- 2000 Watt (400 Watt × 5 beams) Total laser power in the FZ region
- 500 °C ~ 3000 °C FZ Temperature range (depending on material)
- Temperature monitoring from 900 °C to 3500 °C (radiation thermometer)
- Temperature reproducibility: ±1 °C over the entire temperature range
Crystal growth control
- max. crystal length: 150 mm
- max. crystal diameter: 8 mm
- Growth rate: 0.01 to 300 mm (mm/h)
- Rotation speed: 0.1 to 100 rpm
- Vacuum/pressure in FZ range: 1 x 10-4 Torr up to 10 bar
- FZ environment: External gas provided by user
- Monitoring growth: High vision full HDTV camera
- Control: Ubiquitous PC / Smartphone control from your desk / home possible to remotely monitor the crystal growth process
length 140 cm x width 210 cm x height 200 cm
TbMnO3 Single crystal without cracks that can normally be caused by thermal stresses if the temperature profile is gradual. The laser furnace has a graduated temperature profile.