Stimulated Raman with Broadband LED Stokes Source for Analysis of Glucose

We demonstrate stimulated Raman gain using a broadband LED Stokes source to measure vibrational spectra of aqueous glucose solutions. This versatile and cost-effective method increases Raman signal for a variety of applications. We measured both stimulated Raman and spontaneous Raman spectra of glucose solutions with concentrations up to 10 mM with a photon counter and lock-in amplifier. We built partial least squares regression models based on both stimulated Raman and spontaneous Raman spectral data measured with each instrument for predicting concentrations of the glucose solutions. The stimulated Raman spectra measured with the lock-in amplifier based model had the strongest predictive power and predicted the concentrations of the test set of glucose solutions with a mean squared error value an order of magnitude lower than those of the spontaneous Raman based model.