Electron paramagnetic resonance spectroscopy with photothermal and optoacoustic detection

Electron paramagnetic resonance (EPR) spectroscopy has been performed using optoacoustic piezoceramic detection and photothermal infrared detection. Though the signal-to-noise ratio is lower than in conventional EPR detection at 100 kHz, it compares favorably at low modulation frequencies. These detection techniques offer the opportunity of obtaining EPR depth profiles that cannot be obtained using the conventional technique.