Contact

Dr. Margret Fuchs
Division of Exploration

Phone: +49 351 260 - 4480

Further Links

Laser-Induced Fluorescence Spectroscopy

In Laser-Induced Fluorescence spectroscopy (LIF), a laser stimulates a sample surface, which results in a specific glow. This spectroscopic measurement technique is used to characterize materials as well as their constitutive components fast and precise. The Exploration Division uses the LIF-method as an efficient, non-destructive technology for exploring mineral resources in natural rock. The focus is on critical raw materials such as the rare earth metals, vanadium, chromium, tungsten and molybdenum.


Laserinduzierte Fluoreszenzspektroskopie
In the optical characterization lab at the TU Bergakademie Freiberg, HIF scientists  work on a new laser based technology to identify mineral resources fast and precise.
Photo: HZDR/ Detlev Müller

Goals

  • Expand the spectrum of exploration methods

  • Develop an optical taxonomy for natural materials based on their luminescent properties

  • Implement LIF-methods for exploration, but also for other parts of the value chain, such as process control during extraction, processing or recycling

  • Two-dimensional mapping of samples, such as drill cores or rock samples

  • Develop robust routines for measuring and processing luminescence spectra, and technical implementation

Main Research Focus

  • Measure standards of various rare-earth combinations (phosphates, borates, fluorides) to verify or expand a catalog of specific luminescent properties

  • Apply methods to “natural” samples such as drill cores and rock samples with different content levels and compositions of the desired metals


Technology Development in Cooperation with the TU Bergakademie Freiberg 

The Division of Exploration at the Helmholtz Institute Freiberg for Resource Technology is developing the LIF-method as a mineral-resource technology in close cooperation with the Institute of Applied Physics (IAP) at the TU Bergakademie Freiberg (TUBAF).

  • Division of Exploration:
    • Imaging and image processing as well as development of signal-analysis routines to identify mineral & metalliferous raw materials

    • Integration into the range of spectroscopic methods (absorption spectroscopy, hyperspectral imaging in the fields VNIR-SWIR-MWIR-LWIR)

  • Institute of Applied Physics:
    • Measuring the characteristic luminescence (e.g. spectra, decay behavior) in the optical characterization lab at the Institute for Applied Physics at TUBAF

    • Determining the physical and technical parameters in cooperation with the IAP work group for luminescent spectroscopy


Fluoreszierendes Mineral unter dem Laser
Under the laser: fluorescent mineral 
Photo: HZDR/ Detlev Müller

Function

The LIF-method uses light (photons) of certain wavelengths to stimulate the surface of the sample to emit light. This is induced by lasers with wavelengths in the UV-spectrum (325 nm - 337 nm) and in the range of green light (532 nm), as well as with a continually variable laser (< 500 - 2400 nm). CCD cameras (350 - 1700 nm) or photomultipliers detect the resulting characteristic luminescence spectrum.