Infrared spectral hole burning studies have provided a wealth of information concerning site reorientation of defects in solids and vibrational relaxation dynamics. The most investigated systems appear to be impurities trapped in alkali halides. Limited studies on molecules trapped in noble gas matrices have demonstrated that these systems are good candidates for investigating persistent spectral holes. However, most infrared spectral hole burning studies have been limited by the tunability of commercially available infrared lasers which in turn restricts the spectral feature which can be burned. On the other hand, the tunability of Infrared Free Electron Lasers (IR-FELs) allows for targeting radiation into vibrational of the molecular system under study. We have used the Free Electron Laser-Fourier Transform Infrared Spectroscopy to investigate infrared hole burning of formic acid (HCOOD) isolated in an Ar matrix at a matrix/sample ratio of 4000/1. The results of the FEL radiation tuned to v₂ mode of HCOOD are discussed together with matrix induced frequency shifts and matrix induced band splittings.

Date Published: 27 July 1994
PDF: 12 pages
Proc. SPIE 2138, Longer Wavelength Lasers and Applications, (27 July 1994); doi: 10.1117/12.181346

Published in SPIE Proceedings Vol. 2138:
Longer Wavelength Lasers and Applications
Gabor Patonay, Editor(s)