Abstract

Techniques for spectroscopic surface analysis with high spatial resolution, such as confocal microscopy and scanning near-field optical microscopy, require high-brightness coherent sources capable of rapidly addressing wide spectral ranges in regions corresponding to molecular resonances characteristic of specific functional groups. Here we describe the performance characteristics of a frequency-swept optical parametric oscillator (OPO) rapidly tuneable in the 2700 to 3600cm⁻¹ region where many compounds show characteristic resonances associated with C-H, N-H and O-H stretching modes. The OPO was capable of rapid tuning (200nm/ms) over ranges of up to 900cm⁻¹ within an overall 1440cm⁻¹ tuning range and with output powers of up to 2.37W.

© 2011 Optical Society of America