The Saga of Light-Matter Interaction and Magneto-optical Effects Applications to Atomic Magnetometry, Laser-cooled Atoms, Atomic Clocks, Geomagnetism, and Plant Bio-magnetism
The quest to expand the limited sensorial domain, in particular to bridge the inability to gauge magnetic fields near and far, has driven the fabrication of remedial tools. The interaction of ferromagnetic material with a magnetic field had been the only available technique to gauge that field for several millennium. The advent of electricity and associated classical phenomena captured in the four Maxwell equations, were a step forward. In the early 1900s, the model of quantum mechanics provided a two-way leap forward. One came from the newly understood interaction of light and matter, and more specifically the three-way coupling of photons, atoms' angular momenta, and magnetic field, which are the foundations of atomic magnetometry. The other came from magnetically sensitive quantum effects in a fabricated energy-ladder form of matter cooled to a temperature below that of the energy steps; these quantum effects gave rise to the superconducting quantum interference device (SQUID). Research using atomic magnetometers and SQUIDs has resulted in thousands of publications, text books, and conferences. The current status in each field is well described in Refs. [48,49,38,42] and all references therein. In this work we develop and investigate techniques and applications pertaining to atomic magnetometry. [Full text: eric.corsini@gmail.com]
The quest to expand the limited sensorial domain, in particular to bridge the inability to gauge magnetic fields near and far, has driven the fabrication of remedial tools. The interaction of ferromagnetic material with a magnetic field had been the only available technique to gauge that field for several millennium. The advent of electricity and associated classical phenomena captured in the four Maxwell equations, were a step forward. In the early 1900s, the model of quantum mechanics provided a two-way leap forward. One came from the newly understood interaction of light and matter, and more specifically the three-way coupling of photons, atoms' angular momenta, and magnetic field, which are the foundations of atomic magnetometry. The other came from magnetically sensitive quantum effects in a fabricated energy-ladder form of matter cooled to a temperature below that of the energy steps; these quantum effects gave rise to the superconducting quantum interference device (SQUID). Research using atomic magnetometers and SQUIDs has resulted in thousands of publications, text books, and conferences. The current status in each field is well described in Refs. [48,49,38,42] and all references therein. In this work we develop and investigate techniques and applications pertaining to atomic magnetometry. [Full text: eric.corsini@gmail.com]
This work presents new methods of optical magnetometry developed in the Center for Magneto-Optical Research at the Jagiellonian University. Using rubidium atoms contained in cm-long glass cells and amplitude-modulated laser we have recorded magneto-optical signals of extremely small widths. These signals allow measurements of magnetic fields with a sensitivity comparable to that achieved with magnetometers based on Superconducting Quantum Interference Devices (SQUIDs). Full Text: PDF References: M. Faraday,Experimental Researches in Electricity. Nineteenth Series, Trans. R. Soc. London 136, 1 (1846). [CrossRef] K. Barczak and S. Pustelny,Magnetooptic properties of special optical type D fibers, J. Phys. IV 137, 15 (2006). [CrossRef] W. Gawlik, J. Kowalski, R. Neumann, and F. Trager, Observation of the electric hexadecapole moment of free Na atoms in a forward scattering experiment, Opt. Commun. 12, 400 (1974). [CrossRef] W. Gawlik, S. Pustelny, in New Trends in Quantum Coherence and Optics, R. Drampyan Ed., 47 (New York, Nova Publishers, 2009). D. W. Gawlik, D. F. Kimball, S. M. Rochester, A. Weis, and V. V. Yashchuk,Resonant nonlinear magneto-optical effects in atoms, Rev. Mod. Phys. 74, 1153 (2002). [CrossRef] D. V.V. Yashchuk, and M. Zolotorev,Nonlinear Magneto-optic Effects with Ultranarrow Widths, Phys. Rev. Lett. 81(26), 5788 (1998). [CrossRef] D. D. F. Kimball, S. M. Rochester, V. V. Yashchuk, and M. Zolotorev,Sensitive magnetometry based on nonlinear magneto-optical rotation, Phys. Rev. A 62, 043403 (2000). [CrossRef] G. Wąsik, W. Gawlik, J. Zachorowski, and W. Zawadzki, Laser frequency stabilization by Doppler-free magnetic dichroism, Appl. Phys. B 75, 613 (2002). [CrossRef] W. Gawlik, L. Krzemien, S. Pustelny, D. Sangla, J. Zachorowski, M. Graf, A. O. Sushkov, and D. Budker, magneto-optical rotation with amplitude modulated light, Appl. Phys. Lett. 88 131108 (2006). [CrossRef] D. D. F. Kimball, V. V. Yashchuk, M. Zolotorev,Nonlinear magneto-optical rotation with frequency-modulated light, Phys. Rev. A 65, 055403 (2002). [CrossRef] J. M. Higbie, E. Corsini, and D. Robust, high-speed, all-optical atomic magnetometer, Rev. Sci. Instr. 77, 113106 (2006). [CrossRef] S. Pustelny, A. Wojciechowski, M. Kotyrba, K. Sycz, J. Zachorowski, W. Gawlik, A. Cingoz, N. Leefer, J. M. Higbie, E. Corsini, M. P. Ledbetter, S. M. Rochester, A. O. Sushkov, and D. All-optical atomic magnetometers based on nonlinear magneto-optical rotation with amplitude modulated light, Proc. of SPIE 6604, 660404 (2007). [CrossRef] S. Pustelny, A. Wojciechowski, M. Gring, M. Kotyrba, J. Zachorowski, W. Gawlik, Magnetometry based on nonlinear magneto-optical rotation with amplitude-modulated light, J. Appl. Phys. 103, 063108 (2008). [CrossRef] S. Pustelny, S. M. Rochester, D. F. Jackson Kimball, V. V. Yashchuk, D. and W. Gawlik, Nonlinear magneto-optical rotation with modulated light in tilted magnetic fields, Phys. Rev. A 74, 063420 (2006). [CrossRef]
There has been permanent interest in investigations of new magnetic sensors and their various applications (Edelstein, 2007). Last years there is a rapid progress in development of magneto-optical sensors because of their sensitivity and potential for miniaturization. Magnetometers, based on magneto-optical sensors have high sensitivity comparable to, or even surpassing this of the SQUIDs (Superconducting Quantum Interference Devices) (Kominis et al., 2003; Dang et al., 2010; Savukov, 2010; Knappe, 2010). Microfabrication of components using the techniques of Micro-Electro-Mechanical Systems (MEMS) developed for atomic clocks (Knappe, 2004) gives the opportunity for building small, low consuming, low cost and non-cryogenic (as SQUIDs) sensors (Griffith et al., 2010). Coherent optical effects can be applied for magnetic field detection and offer perspectives for development of high-precision optical magnetometers (Cox et al., 2011; Kitching et al., 2011). These magnetometers are appropriate for geomagnetic, space, nuclear and biological magnetic field measurements (cardio and brain magnetic field imaging), environmental monitoring, magnetic microscopy, investigations of fundamental physics, etc. Coherent magneto-optical resonances have many applications not only in magnetometry, but in high-resolution spectroscopy, lasing without inversion, laser cooling, ultraslow group velocity propagation of light, etc. (Gao, 2009).
Advances in Optical and Photonic Devices 330 integration into microfabricated packages.Such packages will be not only inexpensive and easy to batch produce they will also have lower power consumption, light weight and unimpeded mobility (Knappe et al., 2006).Sensitive magnetic field measurements, for which AMs can be used, are important owing to many existing and potential applications.Magnetometers have been in wide use, for example, in geology, military, biomagnetism, space magnetic field measurements.AMs have been used because they are both relatively sensitive compared to conventional inexpensive magnetometers, such as fluxgates, and more convenient compared to SQUIDs that require cryogenic cooling.For a long time low-T c SQUIDs had been by far the most sensitive magnetometers at low frequency.However, this has changed with the demonstration with AMs of record 0.5 fT/Hz 1/2 sensitivity (Kominis et al., 2003).High-sensitivity AMs are based on spin-polarized atomic gases or vapors, and AM research is closely related to the atomic physics subfield dedicated to the investigation of spin interactions in such media.This subfield includes the research on optical pumping and related topics such as atomic clocks, masers, hyperpolarized gases, spin-based spectroscopy, and some others.A comprehensive review of optical pumping experiments before 1972 and theory of optical pumping and various relaxation mechanisms are given by William Happer (Happer, 1972).This theory, which still stands the test of time, includes the formulation of density matrix equations, which can be directly applied to the analysis of magnetic resonances of vapors on which atomic magnetometers are based.Atomic magnetometers find many applications as other magnetometers, but they are most useful when high sensitivity and non-cryogenic operation are required.For example, AMs have been developed for submarine detection, and many other military applications are possible on similar principles.Some applications of Rb-vapor or 3 He magnetometers in geophysics and space physics were mentioned as early as in 1961 by Bloom (Bloom, 1961) who did some pioneering work on the high-sensitivity measurements of magnetic fields and theory for the operation of atomic magnetometers.Theoretical analysis of early atomic magnetometers was also done by Dehmelt (Dehmelt, 1957) and by Bell and Bloom (Bell & Bloom, 1957).Although the history of atomic magnetometers is quite fascinating and they played an important role in applications where simpler and less expensive methods did not provide sufficient sensitivity, the atomic magnetometers of the past were much less sensitive than the modern ones.Most exciting results appeared only recently with the various demonstrations of performance of high-density AMs, which we would like to focus on in this chapter. How to referenceIn order to correctly reference this scholarly work, feel free to copy and paste the following: Igor Savukov (2010).Ultra-Sensitive Optical Atomic Magnetometers and Their Applications, Advances in Optical and Photonic Devices, Ki Young Kim (Ed.),
Introduction Shortly after the inception of atomic magnetometry, alkali-vapor magnetometers were being used to measure the Earth's magnetic field to unprecedented precision. During the same era, Bell and Bloom first demonstrated all-optical atomic magnetometry through synchronous optical pumping [1] (see Chapters 1 and 6). In this approach, optical-pumping light is frequency- or amplitude-modulated at harmonics of the Larmor frequency ω L to generate a precessing spin polarization within an alkali vapor at finite magnetic field [2, 3]. Although this technique received considerable attention from the atomic physics community for its applicability to optical pumping experiments, Earth's-field alkali-vapor atomic magnetometers continued to rely on radiofrequency (RF) field excitation for several decades (see Chapter 4). Upon the advent of diode lasers addressing alkali and metastable helium transitions, synchronously pumped magnetometers experienced a revival beginning in the late 1980s. In recent years, such magnetometers have found applications in nuclear magnetic resonance detection [4] (see also Chapter 14), quantum control experiments [5], and chip-scale devices intended for spacecraft use [6] (see also Chapters 7 and 15). All-optical magnetometers possess several advantages over devices that employ RF coils. RF-driven magnetometers can suffer from cross-talk if two sensors are placed in close proximity, since the AC magnetic field driving resonance in one vapor cell can adversely affect the other. All-optical magnetometers are free from such interference. When operated in self-oscillating mode [7], RF-driven magnetometers require an added ±90° electronic phase shift in the feedback loop to counter the intrinsic phase shift between the RF field and the probe-beam modulation.
Featuring chapters written by leading experts in magnetometry, this book provides comprehensive coverage of the principles, technology and diverse applications of optical magnetometry, from testing fundamental laws of nature to detecting biomagnetic fields and medical diagnostics. Readers will find a wealth of technical information, from antirelaxation-coating techniques, microfabrication and magnetic shielding to geomagnetic-field measurements, space magnetometry, detection of biomagnetic fields, detection of NMR and MRI signals and rotation sensing. The book includes an original survey of the history of optical magnetometry and a chapter on the commercial use of these technologies. The book is supported by extensive online material, containing historical overviews, derivations, sideline discussion, additional plots and tables, available at www.cambridge.org/9781107010352. As well as introducing graduate students to this field, the book is also a useful reference for researchers in atomic physics.
Mechanical effects of light are considered in the first section of Chapter 7, together with their application to “optical tweezers.” This leads naturally to a discussion of laser cooling by a variety of techniques. Doppler cooling, magneto‐optic traps, sub‐Doppler cooling, and velocity‐selective coherent population trapping (VSCPT) are all covered. Then coherent population transfer is analyzed as a counterintuitive way of altering the occupation of energy levels in an exceptionally efficient manner. Coherent transverse optical magnetism, covered next, is the only example in the book of an optical effect mediated by the magnetic field of light. This phenomenon is characterized by intense emission of magnetic rather than electric dipole radiation at only moderate intensities and theoretically enables negative indices of refraction and spin control in unstructured, natural (nonmagnetic) materials. Electromagnetically induced transparency (EIT) is also described. This phenomenon is based on tri‐level coherence and can turn opaque media transparent over a limited bandwidth. Additionally, it can intensify high‐order nonlinear optical processes via intermediate step enhancement that is fully resonant. It has been applied to slow or store light as well. In this final chapter, squeezed light is given as an example of a coherent state with altered noise properties. Because the noise in squeezed quadratures of such a state can be reduced below the shot noise limit, it has applications to precision measurements and secure communication. The final section is on cavity quantum electrodynamics (QED). This topic treats the interaction of atoms with weak fields that are enhanced through the use of external cavities. In cavity QED, single photons can interact strongly enough with atoms to exhibit Rabi‐splitting behavior, and the strong coupling limit is considered to be a viable approach to quantum computation.