Fig. 4: Absorbance vs concentration measurements at 1597 cm−1.
From: A mid-infrared lab-on-a-chip for dynamic reaction monitoring

Results in absorbance units (AU) of the QCLD sensor for BSA in D2O with (red stars) and without (blue squares) 18-mV crosstalk correction (left scale) and in comparison to the single-reflection ATR-FTIR system (violet circles, right scale). The right scale is divided by a factor of 10 as compared to the left one for better visibility of the ATR-FTIR signal.