Laser-heated floating zone furnace LFZ

The Laser-Heated Floating Zone Furnace is a space- and resource-saving solution for advanced float zone crystal growth. This full-featured furnace is ideal for laboratories and research facilities focused on crystal growth and advanced materials development. What truly sets it apart is its compact design, which not only saves valuable laboratory space but also drastically reduces the acquisition costs. Utilizing 5 independent, 330 W and 980 nm diode lasers in its standard configuration, the furnace is ready to accommodate 3, 4, or 7 lasers, depending on the user’s requirements. It offers step-less power control, allowing for melting temperatures between 300 °C and 3000 °C. Standard laser beam geometries are 4 x 6 mm and 4 x 4 mm, with a sharp cut-off edge on the lower laser beam rim. The gas management system can handle pressures up to 10 bar and gas flow values between 0.1 and 1 l/min. The process observation includes a high-resolution CCD camera with HDR image optimization and precise two-color pyrometer for real-time temperature measurement. The furnace has a comfortable GUI for all PLC-based adjustments, and several advanced power ramp and travelling ramp functions are adaptable. The material rod is moved with precise linear and rotation feed-through systems, and the pulling rate can be varied from 0.1 mm/h to 200 mm/h, with a pulling length (max. crystal length) of 150 mm.  Harnessing the power of laser heating technology, this advanced furnace is designed to deliver exceptional results with efficiency and convenience.



Laser heating

  • Standard configuration: 5 x 330 W (total 1.65 kW) diode lasers for homogeneous radial power distribution
  • Ready to be used with 3, 4 and 7 laser within the same housing
  • Laser wavelength 980 nm
  • Step-less power control, melting temperatures between 300 °C and 3000 °C (material dependent)
  • Laser beam geometry: standard configuration 4 x 6 mm and 4 x 4 mm (other beam sizes available on request)
  • High power uniformity within the laser beam spot due to optimized optical components



  • Argon and oxygen (pure and in any mixture)
  • Many other gases also possible
  • Gas pressure inside the growth chamber: 10-1 mbar to 10 bar
  • manually controlled gas flow 0.1 to 1 l/min
  • Each gas adjustable individually and independently


Pulling drives

  • Precise linear and rotation feed through systems
  • Pulling rate: 0.1 mm/h to 200 mm/h
  • Fast gear mode
  • Pulling length (max. crystal length): 100 mm (150 mm on request)
  • Rotation rate: 0 to 70 rpm


Process control

  • High-resolution CCD camera with HDR image optimization
  • Precise two-color pyrometer for real time temperature measurement
  • Monitoring software: visual control, video recordings, snapshots and length measurements during the process
  • Several advanced power ramp and travelling ramp functions adaptable
  • Comfortable GUI for all PLC-based adjustments


Required lab connections

  • Gas supply with 12 bar pressure
  • Exhaust air system
  • Energy supply


Furnace dimensions

  • Height: 1900 mm, width: 780 mm, depth: 1100 mm
  • All components are integrated into the housing (electronics, laser power supply, gas management)
  • Modular housing in the 4-laser setup available to meet space requirement for beamline experiments
Figure above: Full-featured compact laser-heated FZ furnace with several diode lasers à 330 W and 10 bar process gas pressure
Figure above: Visualization of the LFZ process chamber room with 5 laser beams
Figure above:   LFZ laser spots have 4 mm diameter with a sharp cut-off edge at the lower rim for optimal formation of the crystallization plane; shown for the 5-laser option
Figure above:   LFZ  is  ready  to  be  equipped  with 3, 4, 5 or 7 lasers
Figure above: 4-laser configuration is designed for in-situ X-ray investigations of crystallization processes or hight-temperature diffraction studies