Solid state multi-wavelength laser development for planetary science laser mass spectrometer

Laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) is a versatile technique used for identifying the composition of geological materials and quantifying element abundances. The PLASMA (Pulsed Laser Ablation Sampling and Mass Analysis) investigation, supported through the NASA DALI (Development and Advancement of Lunar Instrumentation) program, is focused on the technical development of an LA-ICPMS instrument comprising a multi-wavelength pulsed laser, low power plasma source, collision cell designed to separate Rb and Sr for radiometric dating, and heritage quadrupole mass spectrometer based on the analyzer flown on the Sample Analysis at Mars (SAM) instrument onboard the Curiosity rover [1]. Multi-wavelength laser pulses at 1064 nm, 532 nm, 266 nm, and 213 nm enable the analysis of water-bearing phases, support Raman spectroscopy, enhance the desorption of aromatic hydrocarbons, and promote the ablation of refractory geological phases, respectively. We report on the PLASMA's solid-state, multi-wavelength pulsed laser technology development. The fundamental 1064 nm laser, based on heritage spaceborne laser transmitter design, generates 4mJ, 5 ns pulses at 10 Hz from ceramic Nd:YAG slab oscillator pumped by 885 nm laser diode array. The ceramic Nd:YAG is highly doped with similar to 4 at% Nd, and with the use of an 885 nm in-band pumping, allows to operate at similar to twice the nominal performance of a 1% crystalline Nd:YAG pumped with 808 nm diode. Second, fourth and fifth harmonic generation of the fundamental laser is achieved using LBO and BBO crystals with optimizing the output energies of 532 nm, 266 nm, and 213 nm to reach the energy fluences up to 5 J/cm(2). The wavelength of laser output is selectable on-demand.