Laser Induced Breakdown Spectroscopy

1
Laser Induced Breakdown Spectroscopy
Phi Hung Thanh Advisor Christopher
Dreyer Colorado School of Mines, Golden, Colorado

• Project Objectives
• Obtain spectroscopy data from solid samples
• Use low power laser and fiber optics for beam
  delivery
• Design compatible system for Space Exploration
• Research laser to fiber coupling

Collected Data

• Tracing Laser beam
• Knowing beam radius, wo, enable control of fiber
  coupling conditions
• Thin lens approximation can be use to approximate
  beam radius
• Thin lens approximation also allows optimizing
  optical system design

Plot of laser beam trace using Mathematica and
thin lens approximation

• Introduction
• LIBS ablates solid material into plasma and
  obtain spectra information
• Main issue lies with focusing relatively low
  power laser into a small high-power spot
• Delivering maximum laser energy directly depends
  to coupling laser into fiber

• Propose application
• Use in space exploration to quickly determine the
  material of solids
• Integrating sampling system in drill heads

Illustration of how LIBS is obtained
Beam radius at entry point into fiber (woprime3)
vs position of lens 2 (zpos2) in Mathematica
using thin lens approximation and optimization
methods to design optical system.

• Conclusion and Future Research
• Initial phase of theoretical work completed
• Experimental phase next semester
• Design and build probe head once data is
  collected and determine fiber with best
  transmitting property.

Sample Spectral data obtained through LIBS of
Limestone sample
Possible rover obtaining LIBS data from rocks