We present experimental demonstrations using a broadly tunable external cavity quantum cascade laser (ECQCL) to perform Reflection-Absorption InfraRed Spectroscopy (RAIRS) of thin layers and residues on surfaces. The ECQCL compliance voltage was used to measure fluctuations in the ECQCL output power and improve the performance of the RAIRS measurements. Absorption spectra from self-assembled monolayers of a fluorinated alkane thiol and a thiol carboxylic acid were measured and compared with FTIR measurements. RAIRS spectra of the explosive compounds PETN, RDX, and tetryl deposited on gold substrates were also measured. Rapid measurement times and low noise were demonstrated, with
Revised: July 30, 2013 |
Published: February 4, 2013
Citation
Phillips M.C., I.M. Craig, and T.A. Blake. 2013.Reflection-Absorption Infrared Spectroscopy of Thin Films Using an External Cavity Quantum Cascade Laser. In Quantum Sensing and Nanophotonic Devices X, February 2, 2013, San Francisco, California. Proceedings of the SPIE, edited by M Razeghi, 8631, Paper No. 86310C. Bellingham, Washington:SPIE.PNNL-SA-92467.doi:10.1117/12.2002849