Sensitive and ultra-fast detection using pulsed cavity ringdown spectroscopy

A. Alquaity, E. Essebbar, A. Farooq
Optics Express, Issue 23, 7217-7226, (2015)

Sensitive and ultra-fast detection using pulsed cavity ringdown spectroscopy

Keywords

High-sensitivity diagnostic

Abstract

​Pulsed cavity ringdown spectroscopy (CRDS) is used to develop a novel, ultra-fast, high-sensitivity diagnostic for measuring species concentrations in shock tube experiments. The diagnostic is demonstrated by monitoring trace concentrations of ethylene in the mid-IR region near 949.47 cm−1. Each ringdown measurement is completed in less than 1 µs and the time period between successive pulses is 10 µs. The high sensitivity diagnostic has a noise-equivalent detection limit of 1.08 x 10−5 cm−1 which enables detection of 15 ppm ethylene at fuel pyrolysis conditions (1845 K and 2 bar) and 294 ppb ethylene under ambient conditions (297 K and 1 bar). To our knowledge, this is the first successful application of the cavity ringdown method to the measurement of species time-histories in a shock tube.

Code

DOI: 10.1364/OE.23.007217

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