Spectral fingerprinting of aqueous glucose with ultra-broadband vibrational sum-frequency generation spectroscopy at bio-relevant low concentration

Vibrational modes of glucose spanning from 900 to 1400 cm-1 in the molecular fingerprint region have been traced by means of vibrational sum-frequency generation spectroscopy in aqueous solution as a function of glucose concentration. The high sensitivity is enabled by a 200 kHz few-cycle mid-infrared optical parametric chirped-pulse amplifier (OPCPA). The OPCPA generates broadband pulses (from 7 to 11 mu m) centered at 9 mu m with 114 fs pulse duration, at a high average power of 245 mW and high pulse energy of 1.2 mu J. The achieved performance of the spectrometer is benchmarked by probing the carbon-oxygen bond stretching mode at 1035 cm-1 using a biologically relevant low sample concentration of 10 mM. Published by Optica Publishing Group under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.