Low-noise surface-enhanced mid-infrared laser absorption spectroscopy based on spectrum compensation

Spectrum compensation methods hold the potential to decrease the limit of detection in absorption spectroscopy. We report a spectrum compensation method for a home-built surface-enhanced mid-infrared laser absorption spectroscopy detection system to reduce the noise of the system. The measurement results of the spectrum compensation method show that the fluctuations in the single beam spectrum covering 1640-977 cm-¹ are smaller. Meanwhile, the dynamic range noise and the detector noise are both reduced by 4 times, the shot noise is reduced by 2 times, and the root-mean-square noise of 100% line is reduced by 1.6 times.