Photoacoustic Spectroscopy and Its Applications – A Tutorial Review

Based on photoacoustic effect, photoacoustic spectroscopy is an unusual form of spectroscopy which uses both light and sound and is based on the absorption of electromagnetic radiation by analyte molecule. The absorbed energy is measured by detecting pressure fluctuations in the form of sound waves or shock pulses. A photoacoustic spectrum consists of a plot of the intensity of the acoustic signal detected by a microphone or a piezoelectric detector, against the excitation wavelength or another quantity related to the photon energy of the modulated excitation. It is a valuable source for data acquisition relating to absorption and material science studies.