A high dynamic range handheld LIBS spectrometer and its applications

Katherine Bakeev, Qun Li, Dan Liu, Jing Li, and Sean Wang
B&W Tek, Delaware, United States

Keywords: laser-induced breakdown spectroscopy (LIBS), high repetition rate micro-pulse laser, field testing

Development of a handheld LIBS spectrometers is a key step of introducing LIBS technology into field applications. Handheld LIBS spectrometers generally rely on miniature CCD array spectrometers which do not have active temperature control, and suffer from a limited dynamic range due to their relatively shallow well depth and high readout and dark noise. We present a handheld LIBS spectrometer with a high dynamic range of >10,000 based on a micro-pulse excitation laser with a high repetition rate. The laser beam is scanned over the sample, generating several thousands of micro plasma emissions per second. A synchronized miniature CCD array spectrometer module integrates the LIBS signal produced by the micro plasma emissions. By measuring the LIBS signal at a short and a long integration time and mathematically combining the two spectra, the dynamic range of the LIBS spectrum is enhanced by over one order of magnitude. Mobility and portability of instrumentation is opening the door for targeted measurement solutions at the point of need. Technological developments have taken the solutions to the samples allowing for rapid screening and response. We will present examples of applications ranging from heavy metal contamination in water to rapid material screening.