A5042551108- Quantum optics and atomic interactions
- Laser-Matter Interactions and Applications
- Atomic and Subatomic Physics Research
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Fiber Laser Technologies
- Crystallography and Radiation Phenomena
- Laser-Plasma Interactions and Diagnostics
- Atomic and Molecular Physics
- Photorefractive and Nonlinear Optics
- Quantum Information and Cryptography
- Spectroscopy and Quantum Chemical Studies
- Lanthanide and Transition Metal Complexes
- Photonic Crystals and Applications
- Laser Design and Applications
- Terahertz technology and applications
- Mechanical and Optical Resonators
- Solid State Laser Technologies
- Random lasers and scattering media
- Photonic and Optical Devices
- Advanced NMR Techniques and Applications
- Laser-induced spectroscopy and plasma
- Topological Materials and Phenomena
- Nonlinear Dynamics and Pattern Formation
- Spectroscopy and Laser Applications
- Advanced X-ray Imaging Techniques
Texas A&M University
2015-2024
Mitchell Institute
2009-2024
Institute of Applied Physics
2001-2013
Russian Academy of Sciences
1990-2013
Université Libre de Bruxelles
1990-2005
Max Planck Institute of Quantum Optics
1993-1999
Technical University of Munich
1997
Drexel University
1992
University of New Mexico
1992
We study the propagation of a bichromatic field in three-level and four-level media. In case medium, we consider \ensuremath{\Lambda} configuration demonstrate that if upper level is not empty there critical value for low-frequency coherence such below this threshold intense fields, coherent bleaching occurs. This implies sharp reduction absorption fluorescence emission whereas above parametric instability takes place. It corresponds to an amplification does need population inversion between...
We prove that it is possible to freeze a light pulse (i.e., bring full stop) or even make its group velocity negative in coherently driven Doppler broadened atomic medium via electromagnetically induced transparency (EIT). This remarkable phenomenon of the ultraslow EIT polariton based on spatial dispersion refraction index n(omega,k), i.e., wave number dependence, which due motion and provides contribution velocity. related to, but qualitatively different from, recently observed slowing...
We study basic issues central to the storage of quantum information in a coherently prepared atomic medium such as role adiabaticity. also propose and demonstrate transporting, multiplexing, time reversing stored light.
We derive an analytic expression for the linewidth of electromagnetically induced transparency (EIT) resonance in a Doppler-broadened system. It is shown here that relatively low intensity driving field EIT proportional to square root and independent Doppler width, similar laser-induced line narrowing effect described by Feld Javan. In limit high we recover usual power-broadening case where inversely width.
Resonant oscillators with stable frequencies and large quality factors help us to keep track of time high precision. Examples range from quartz crystal in wristwatches atomic clocks, which are, at present, our most precise measurement devices1. The search for more convenient reference is continuing2-6. Nuclear are better than because their naturally higher resilience against external perturbations7-9. One the promising cases an ultra-narrow nuclear resonance transition 45Sc between ground...
We study all possible resonant three-level configurations where a low-frequency coherent pump can be converted into high-frequency field in the absence of population inversion at both atomic transitions. identify two different mechanisms that provide such inversionless amplification.
We show that there is no need for adiabatic passage in the storage and retrieval of information optically thick vapor Lambda-type atoms. This can be mapped into retrieved out long-lived atomic coherence with nearly perfect efficiency by strong writing reading pulses steep rising falling edges. elucidate similarities differences between ``adiabatic'' ``instant'' light techniques, conclude any switching time, an almost possible if group velocity signal pulse much less than speed vacuum c...
Optical quantum memories are key elements in modern technologies to reliably store and retrieve information. At present, they conceptually limited the optical wavelength regime. Recent advancements x-ray optics render an extension of memory protocols ultrashort wavelengths possible, thereby establishing photonics at energies. Here, we introduce protocol that utilizes mechanically driven nuclear resonant
We analyze the physical origin of inversionless amplification in four-level atoms driven by a Raman field and identify existence two different mechanisms for predicted gain. The first mechanism is connected with appearance population inversion between atomic states dressed coherent pump, while second linked to buildup coherence among these states. Proper selection relaxation parameters can make either or dominant over other although usually both coexist.
We generalize the theory of electromagnetically induced transparency (EIT) and slow group velocity for case homogeneous inhomogeneous line broadening in both one- two-photon transitions which unavoidably takes place solid materials with a long-lived spin coherence. identify regimes EIT where linewidth can be essentially reduced due to and, moreover, proportional amplitude driving field rather than intensity. suggest also class materials, namely, rare-earth ion doped semiconductors or...
We introduce decaying-dressed states for a three-level Λ system driven at one atomic transition and probed the adjacent one. These allow simple interpretation classification of various coherent effects in such system.
A compound nuclear-electron system driven by a coherent optical field and probed at the gamma-ray M\"ossbauer transition is analyzed for first time. The possibility of control spectra predicted. This study provides basis new branch spectroscopy, laser-M\"ossbauer opens prospects realization laser.
A significant reduction of absorption for single gamma photons has been experimentally observed by studying Mössbauer spectra 57Fe in a FeCO3 crystal. The experimental results have explained terms quantum interference effect involving nuclear level anticrossing due to the presence combined magnetic dipole and electric quadrupole interaction.
We propose a method to transform single photon field into bunches of pulses with controllable timing and number in bunch. This is based on transmission through an optically thick single-line absorber vibrated frequency appreciably exceeding the width absorption line. The spectrum quasi-monochromatic incoming 'seen' by as comb equidistant spectral components separated vibration frequency. Tuning resonance m-th component transforms output radiation m each experimentally demonstrated proposed...
It was shown by Kocharovskaya and Khanin [Sov. Phys. JETP 63, 945 (1986)] that a comb of optical pulses can induce ground-state atomic coherence change the response an medium. In our experiment, we studied propagation produced mode-locked diode laser in rubidium vapor. Electromagnetically induced transparency (EIT) observed when pulse repetition rate is subharmonic hyperfine splitting ground state. The width EIT resonance determined relaxation coherence. Possible applications to...
A strong coherent field drastically modifies the spontaneous decay of three-level atoms when one dynamic Stark sublevel crosses a neighboring atomic state. This leads to an anomalous response yielding maximal coherence, vanishing absorption, and ultralarge index refraction.
The radiation burst from a single $\ensuremath{\gamma}$-photon field interacting with dense resonant absorber is studied theoretically and experimentally. This effect was discovered for the fist time by P. Helisto et al. [Phys. Rev. Lett. 66, 2037 (1991)] it named ``gamma echo.'' echo generated 180${}^{\ensuremath{\circ}}$ phase shift of incident field, attained an abrupt change position respect to source during coherence photon wave packet. Three distinguishing cases gamma are considered;...
We propose a universal method to produce extremely short pulses of electromagnetic radiation in various spectral ranges. The essence the is resonant interaction with atoms under conditions adiabatic periodic modulation atomic transition frequencies by far-off-resonant control laser field via dynamic Stark shift levels and proper adjustment intensity frequency, as well optical depth medium. potential illustrated an example hydrogenlike system.
The pulsed radiation field propagating in a thick resonant absorber induces the polarization (quantified by induced atomic dipoles optical domain or nuclear transition moments gamma domain), which is distributed oscillatorily along forming sandwich of layers with opposite phases. As result, reemitted, scattered fields different interfere incident input destructively constructively, giving rise to well-known dynamical beats output radiation. We propose method how force these reemit phase...