Method for examining the nuclear magnetic resonance in a sample and device for carrying out the method

摘要

Nuclear magnetic resonance in a sample volume located in a measuring volume is examined by generating a packet of laser pulses to act on the measuring volume when a quasi-static magnetic field occurs therein. If the resonance conditions for nuclear spins contained therein are fulfilled, the sample volume emits a response signal that is received by a detector. The quasi-static magnetic field occurring within the measuring volume is generated by acting on the measuring volume with a low-frequency laser beam having a wavelength that exceeds the wavelength of the excitation laser by at least 10² to create a periodically variable magnetic field in the measuring volume. The amplitude of the field is at least 90% of the maximum thereof in the measuring volume. Alternatively, the measuring volume is acted on by a high-frequency laser beam having a frequency exceeding the frequency of the excitation laser by at least 10². The laser beam is subjected to rectification before acting on the measuring volume to create a quasi-static magnetic field in the measuring volume having an effective mean constant flux density over at least 10 periods, wherein the spatial and time average of the flux density are not equal to zero.