Abstract

We present what is to our knowledge the first comprehensive far-infrared absorption measurement of flames. These measurements, covering the region of 7–88 wave numbers (0.2–2.65 THz) are only now made possible by the technique of terahertz time-domain spectroscopy. We observe a large number of absorption lines— including those of water, CH, and NH₃—in a stationary, premixed, propane–air flame. The absorption strength permits the determination of species concentration along the beam path. The flame temperature is determined by comparison of the relative strengths of the water vapor lines.

© 1995 Optical Society of America

Far-infrared time-domain spectroscopy with terahertz beams of dielectrics and semiconductors

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