A review of spectral broadening in laser atomic absorption spectroscopy

Laser atomic absorption spectroscopy (LAAS) has played a significant role in various fields such as nuclear forensics, chemical detection, medical diagnostics, environmental monitoring, and various industrial sectors, leveraging its unique advantages. However, spectral broadening phenomena significantly impact the accuracy and precision of LAAS measurements. This critical review examines spectral broadening and its implications for LAAS, incorporating recent advances in ultrafast diagnostics, extreme plasma conditions, and data-driven modeling. The convolution of various broadening mechanisms results in the final profile of spectral lines, among which Doppler, Stark, and pressure broadening are the primary sources in LAAS. Though spectral broadenings generally introduce measurement errors, they also provide crucial information about plasma characteristics. The review concludes with future perspectives, highlighting emerging technologies including artificial intelligence and novel suppression strategies that promise to enhance LAAS capabilities beyond current limitations.