Fundamental Noise Characteristics of Chirped Laser Dispersion Spectroscopy

Analysis of the fundamental noise characteristics of chirped laser dispersion spectroscopy (CLaDS) is reported. The noise performance of CLaDS under shot noise conditions is investigated and the results are compared to that of direct laser absorption spectroscopy (DLAS). For single spectral point detection, the CLaDS detection limit is a factor of 6 higher than that of DLAS. In the case of full spectral fitting with accurate representation of the noise characteristics and the less complex baseline correction in CLaDS, both techniques show comparable fundamental limit of performance in trace-chemical detection.