laser magnetic resonance spectroscopy

physics

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June 30, 2026

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Laser magnetic resonance (LMR) spectroscopy is a technique used to study molecules with permanent magnetic moments, such as free radicals. It utilizes lasers to probe these molecules by applying external magnetic fields to tune energy levels into coincidence with the laser frequency. This method enhances sensitivity by placing the sample inside the laser cavity and modulating the magnetic field, allowing for the detection of very low concentrations of paramagnetic species. LMR spectroscopy has been instrumental in identifying radicals in interstellar space and providing detailed spectral information for them. An analogous technique, Stark spectroscopy, uses electric fields for molecules with electric dipole moments.1

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spectroscopy
Laser magnetic resonance and Stark spectroscopies
Because of the nature of laser-signal generation, most lasers are not tunable over an appreciable frequency range and even those that can be tuned, such as dye lasers, must be driven by a pump laser and for a given…
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Because of the nature of laser-signal generation, most lasers are not tunable over an appreciable frequency range and even those that can be tuned, such as dye lasers, must be driven by a pump laser and for a given…
Read More