Abstract
We demonstrate non-contact remote photoacoustic spectroscopy in the mid-infrared region. A room-temperatureoperated pulsed external-cavity quantum cascade laser is used to excite photoacoustic waves within a semitransparent sample. The ultrasonic waves are detected remotely on the opposite side of the sample using a fiber-optic Mach- Zehnder interferometer, thereby avoiding problems associated with acoustic attenuation in air. We present the theoretical background of the proposed technique and demonstrate measurements on a thin polystyrene film. The obtained absorption spectrum in the region of 1030-1230 cm-1 is compared to a spectrum obtained by attenuated total reflection, showing reasonable agreement.
| Original language | English |
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| Pages (from-to) | 3476-3479 |
| Number of pages | 4 |
| Journal | Optics Letters |
| Volume | 40 |
| Issue number | 15 |
| DOIs | |
| Publication status | Published - Jul 2015 |