Open AccessSingle-shot, planar infrared imaging in flames using polarization spectroscopy
Author(s) -
Zhiwei Sun,
Johan Zetterberg,
Zeyad T. Alwahabi,
Marcus Aldén,
Zhongshan Li
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.030414
Subject(s) - rotational–vibrational spectroscopy , infrared , materials science , optics , spectroscopy , excited state , planar , infrared spectroscopy , polarization (electrochemistry) , laser , laser induced fluorescence , far infrared laser , fluorescence , atomic physics , chemistry , physics , computer graphics (images) , organic chemistry , quantum mechanics , computer science
Planar infrared visualization of species in flames is challenging due to the severe thermal radiation background and relatively weak fluorescence quantum yields from ro-vibration transitions. In this express, we report imaging of molecular species in a flame via an absorption-based coherent optical method, namely infrared polarization spectroscopy (IRPS). Single-shot, planar imaging of hydrogen fluoride (HF) has been achieved in a premixed CH(4)/O(2) Bunsen flame, being seeded with a small amount of SF(6). The HF molecule was excited through a rovibrational transition at around 2.5 µm, which belongs to the fundamental vibration band. High spatial resolution was guaranteed using an orthorgonal pump-probe geometry, and an effective suppression of thermal background emission was achieved owing to the coherent nature of the demonstrated two-dimensional IRPS. Other advantages, e.g. high temporal resolution and species-specificity, are also features of this laser-based technique, which make it suitable for imaging of non-fluorescent but infrared active gaseous molecules in harsh environments.