Photoacoustic spectroscopy of β-hematin

Laser Photoacoustic Spectroscopy

Fig. 7 — Principle of the photoacoustic effect. Photoacoustic spectroscopy (PAS), also known as optoacoustic spectro­ scopy, was pioneered by Alexander Graham Bell more than a century ago. The advent of the laser strongly stimu­ lated research and applications of this technique and the interest is such that international topical meetings on photo­ acoustic and photothermal phenomena are now hel...

Synchrotron infrared photoacoustic spectroscopy

The use of synchrotron radiation ~SR! as a farand mid-infrared source in the measurement of photoacoustic Fourier transform infrared spectra of solids is demonstrated for the first time in this work. Initial experiments were performed at beamline U10A at the National Synchrotron Light Source, Brookhaven National Laboratory. For synchrotron photoacoustic spectroscopy to be feasible, it must yiel...

Quartz-enhanced photoacoustic spectroscopy.

A new approach to detecting a weak photoacoustic signal in a gas medium is described. Instead of a gas-filled resonant acoustic cavity, the sound energy is accumulated in a high- Q crystal element. Feasibility experiments utilizing a quartz-watch tuning fork demonstrate a sensitivity of 1.2x10(-7) cm(-1) W/ radicalHz . Potential further developments and applications of this technique are discus...

FT-IR Photoacoustic Spectroscopy

Nonlinear photoacoustic spectroscopy of hemoglobin.

As light intensity increases in photoacoustic imaging, the saturation of optical absorption and the temperature dependence of the thermal expansion coefficient result in a measurable nonlinear dependence of the photoacoustic (PA) signal on the excitation pulse fluence. Here, under controlled conditions, we investigate the intensity-dependent photoacoustic signals from oxygenated and deoxygenate...