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The response of a SERF atomic magnetometer to a repetitive short-pulsed pump was investigated. Quantum sub-resonances at a repetition rate of $1/n$ of the Larmor frequency of the magnetic field inside the shield are experimentally observed and theoretically explained. This is a type of synchronization phenomenon. Investigations in single alkali atoms cells as well as mixed alkali atoms of K and Rb are presented. In the later, one species is pumped while the probe is on the other specie polarized by spin exchange. The effect of spin destruction, spin exchange and collisions are studied in order to account for the width of the resonances. Quantum calculations of a three levels $\Lambda$ model for this phenomenon exhibit a dip at the resonance frequency in the absorption spectrum for both cases of pulsed and CW pump modes and an evidence for EIT., Comment: 14 pages, 11 figures

This article presents a method to determine the magnetic field distribution within the vapor cell of a spin-exchange relaxation-free (SERF) atomic magnetometer with a sensitivity of the order of 10 femtoTesla and a bandwidth of DC to 100 Hz, in the presence of an uncompensated ambient magnetic field of up to several nanoTesla. The method is based on the analysis of the atomic polarization in a multichannel pump–probe configuration, in which a spatially selective optical pumping enables to probe specific layers of the atomic vapor contained in a gas-buffered cell. An SERF magnetometer is inherently sensitive to one component of the magnetic field, orthogonal to the pump and probe laser beams. The sensor’s performance can be drastically degraded by the other uncompensated components of the magnetic field. Typically, SERF magnetometry requires very good magnetic shielding and active compensation of residual magnetic field to properly function; this is commonly achieved by applying a complex design of Helmholtz coils in a sophisticated compensation procedure. The method suggested in this article eliminates the influence of non-uniform residual magnetic fields on the accuracy of measurements without precise compensation of the interfering field components. This procedure is used to simplify the measurements of magnetic field distribution in a large vapor cell with required accuracy. This is critically important for precise multichannel magnetic field mapping used for localization of the magnetic dipole-field source.

We present experimental data and theoretical interpretation of NMR spectra of remotely magnetized samples, detected in an unshielded environment by means of a differential atomic magnetometer. The measurements are performed in an ultra-low-field at an intermediate regime, where the J-coupling and the Zeeman energies have comparable values and produce rather complex line sets, which are satisfactorily interpreted., 8 pages, 8 figs, appearing in JMR (2016)

The factorial design technique is implemented to achieve greater accuracy in the determination of magnetic field distribution within a single cell of spin-exchange relaxation-free atomic magnetometer. Three-dimensional magnetic field distribution within a single vapor cell can be found by consecutively pumping, layer by layer, all the cell volumes perpendicular to the probe laser beam, detected by a photodiode array. Thus each element of the array collects information about the magnetic field in the small volume (voxel) which forms when the corresponding part of the probe beam and optically pumped layer cross. One of the most effective ways to enhance measurement accuracy is repeated pumping of the layers and averaging the measured results. However, the measurement time is multiplied several times due to the repeated scanning of the cell volume. The suggested technique enables increased measurement accuracy of each voxel while preserving the number of measurements. Magnetic field distribution is determined by the illumination of the cell layers one by one or simultaneously, according to a special algorithm, with subsequent multifactorial analysis of the obtained results.

We show that a single-cell spin-exchange relaxation-free (SERF) atomic magnetometer can be used for 3-D field measurements. The 3-D operation is achieved by optically pumping the magnetometer cell in successive layers perpendicular to the laser probe beam and by collecting the signals with a photodiode array. The vapor cell is thus divided into voxels acting as local atomic magnetometers. Each voxel's contribution to the probe linear polarization rotation is proportional to the convolution of the local polarization and the magnetic field. The layers are pumped in sequence without waiting for the atomic polarization in the previously pumped layer to relax to zero, consequently, reducing the total measurement time. The photodiode signals are the sum of accumulated linear polarization rotation caused by all the layers. These signals are processed by a deconvolution algorithm that extracts the information originating from each individual voxel. Our theoretical analysis and experimental results show that the time of a single-layer pumping can be reduced below the atomic-cell relaxation time constant, with almost no loss of precision.

We report the observation of the Inverse Cotton-Mouton Effect (ICME) i.e. a magnetization induced in a medium by non resonant linearly polarized light propagating in the presence of a transverse magnetic field. We present a detailed study of the ICME in a TGG crystal showing the dependence of the measured effect on the light intensity, the optical polarization, and on the external magnetic field. We derive a relation between the Cotton-Mouton and Inverse Cotton-Mouton effects that is roughly in agreement with existing experimental data. Our results open the way to applications of the ICME in optical devices.

A multiline spectrum is imposed by intrinsic birefringence in the laser emission of a prism tuned Ti:Sapphire laser, pumped by flashlamp. With certain polarization alignments, the broadband obtained with a tuning prism in the hemispherical cavity is split into 10-20 equally spaced lines of less then 0.05 nm each. The effect, with potential multiline multiplexing applications, is crucial in laser alignment, with implications in Brewster cut crystal processing. The effect produced by the intrinsic birefringence in Ti:Sapphire crystal combined with the polarization introduced by the dispersion prism in the cavity, is explained and calculated for different experimental cases. For specific applications, one may design the multiline spectral separation and the total number of lines of a specific Ti:Sapphire laser. These parameters can be set to permit tunability over a certain range.

A comparative research into the use of Cr4+-doped YAG, YSGG, and LuAG (Lu3Al5O12) as saturable absorbers for the 1.06 micrometer emission of Nd:YAG laser has been conducted. Q-switched pulses with temporal duration ranging from 52 to 23 nsec (FWHM) were observed for the different garnets under investigation. Cross-sections for ground state and excited state absorption were evaluated by fitting our saturation data to Frantz-Nodvik equation. A brief discussion on the use of Cr4+ as a tunable mid-IR laser also is presented.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.