The Experts below are selected from a list of 2625 Experts worldwide ranked by ideXlab platform
Aleksander Rebane - One of the best experts on this subject based on the ideXlab platform.
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controlling pulse delay by light and low magnetic fields slow light in emerald induced by transient Spectral Hole Burning
Optics Letters, 2013Co-Authors: Rajitha Papukutty Rajan, Hans Riesen, Aleksander RebaneAbstract:Slow light based on transient Spectral Hole-Burning is reported for emerald, Be3Al2Si6O18:Cr3+. Experiments were conducted in π polarization on the R1(±3/2) line (E2←A24) at 2.2 K in zero field and low magnetic fields B‖c. The Hole width was strongly dependent on B‖c, and this allowed us to smoothly tune the pulse delay from 40 to 154 ns between zero field and B‖c=15.2 mT. The latter corresponds to a group velocity of 16 km/s. Slow light in conjunction with a linear filter theory can be used as a powerful and accurate technique in time-resolved spectroscopy, e.g., to determine Spectral Hole-widths as a function of time.
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slowing light down by low magnetic fields pulse delay by transient Spectral Hole Burning in ruby
Optics Express, 2012Co-Authors: Hans Riesen, Aleksander Rebane, Alex Szabo, Ivana CarcellerAbstract:We report on the observation of slow light induced by transient Spectral Hole-Burning in a solid, that is based on excited-state population storage. Experiments were conducted in the R1-line (2E←4A2 transition) of a 2.3 mm thick pink ruby (Al2O3:Cr(III) 130 ppm). Importantly, the pulse delay can be controlled by the application of a low external magnetic field B||c≤9 mT and delays of up to 11 ns with minimal pulse distortion are observed for ~55 ns Gaussian pulses. The delay corresponds to a group velocity value of ~c/1400. The experiment is very well modelled by linear Spectral filter theory and the results indicate the possibility of using transient Hole-Burning based slow light experiments as a spectroscopic technique.
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multidimensional holography by persistent Spectral Hole Burning
Journal of Physical Chemistry A, 2002Co-Authors: Alois Renn, Urs P Wild, Aleksander RebaneAbstract:Persistent Spectral Hole Burning (PSHB) in organic molecules doped in a polymer matrix at low temperatures allows optical recording of information in the dimensions of frequency and time, as well as in space and externally applied electric field. We use this special property to demonstrate new types of holograms, which extend conventional spatial-domain optical data storage into the new dimensions. Basic aspects of recording and playback of holograms by persistent Spectral Hole Burning, including relation between frequency- and time-domain response function, is discussed. This paper is elucidating inherent relations between the time-and frequency-domain versions of PSHB holography. We show that by multiplexing holograms in the frequency dimension, we can store a large number (up to 12 000) of image holograms using a single Spectral Hole Burning sample. In the time domain, we show storage and reproduction of ultrashort time-space images on the scale of 10 - 1 2 -10 - 1 3 S. Experiments demonstrating unusual hologram properties, such as causality-related asymmetry of diffraction, inversion of time coordinate, and ultrafast processing, are presented.
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persistent Spectral Hole Burning by simultaneous two photon absorption
Chemical Physics Letters, 2001Co-Authors: Mikhail Drobizhev, Aliaksandr Karotki, Aleksander RebaneAbstract:Abstract We show for the first time persistent Spectral Hole Burning by simultaneous absorption of two 1138 nm photons in an inhomogeneously broadened S 1 ← S 0 ( Q y ) transition of unstable photo-tautomer of chlorin in polymer film at low temperature. Spectrally selective Hole Burning is achieved due to high (10%) quantum efficiency of photo-transformation in that system and high peak intensity (tens of GW/cm2) of near-infrared femtosecond pulses used for excitation. Two-photon absorption cross-section is measured for both stable and unstable photo-tautomers to be σ 2 =(0.5±0.2)×10 −50 cm 4 s photon −1 .
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single femtosecond exposure recording of an image hologram by Spectral Hole Burning in an unstable tautomer of a phthalocyanine derivative
Optics Letters, 2000Co-Authors: Aleksander Rebane, Mikhail Drobizhev, Christophe SigelAbstract:We demonstrate, for what we believe is the first time, recording of a femtosecond image hologram by illumination with a single pair of high-intensity femtosecond pulses in a broad inhomogeneous bandwidth Spectral Hole-Burning material consisting of a polymer film doped with anthraceno-phthalocyanine dye molecules. High efficiency of Spectral Hole Burning is achieved by preillumination of the sample at a low temperature to convert the dye molecules into an unstable tautomer form.
Jean-louis Le Gouët - One of the best experts on this subject based on the ideXlab platform.
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slow light using Spectral Hole Burning in a tm 3 doped yttrium aluminum garnet crystal
Physical Review A, 2009Co-Authors: R Lauro, T Chaneliere, Jean-louis Le GouëtAbstract:We report on light slowing down in a rare-earth-metal-ion-doped crystal by persistent Spectral Hole Burning. The absence of motion of the active ions, the large inhomogeneous broadening, the small homogeneous width, and the long lifetime of the hyperfine shelving states make this material convenient for the Burning of narrow persistent Spectral Holes. Since the Hole can be burnt long before the arrival of the input signal, there is no need for a strong-coupling field, illuminating the sample simultaneously with the input signal, in contrast with procedures such as electromagnetically induced transparency or coherent population oscillations. Analyzing the slowing down process, we point out the role played by the off-resonant atom. Most of the incoming information is carried over to off-resonant atoms, while the pulse is confined within the sample. The observed speed-of-light reduction factor exceeds ${10}^{5}$.
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10 ghz bandwidth rf Spectral analyzer with mhz resolution based on Spectral Hole Burning in tm sup 3 yag
IEEE Photonics Technology Letters, 2005Co-Authors: G Gorju, Jean-louis Le Gouët, V Crozatier, I Lorgere, Fabien BretenakerAbstract:We demonstrate the first 10-GHz instantaneous bandwidth radio-frequency spectrum analyzer based on Spectral Hole Burning in Tm/sup 3+/:YAG. It exhibits 10 000 frequency channels and a resolution better than 1 MHz. Thanks to the fast and linear chirping capabilities of the laser used, it has a potential 100% probability of interception and a response time in the millisecond range. Its linear dynamic range of 16 dB is presently essentially limited by the modest amount of optical power available and can be further improved.
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rf spectrum analysis in Spectral Hole Burning media
on Optical information systems, 2004Co-Authors: Max Colice, Ivan Lorgeré, Friso Schlottau, Kelvin H Wagner, Krishna R Mohan, William R Babbitt, Jean-louis Le GouëtAbstract:We propose a novel, wideband spectrum analyzer based on Spectral Hole Burning (SHB) technology. SHB crystals contain rare earth ions doped into a host lattice, and are cooled to cryogenic temperatures to allow sub-MHz Hole Burning linewidths. The signal spectrum is recorded in an SHB crystal by illuminating the crystal with an optical beam modulated by the RF signal of interest. The signal's Spectral components excite those rare earth ions whose resonance frequencies coincide with the Spectral component frequencies, engraving the RF spectrum into the crystal's absorption profile. Probing this altered absorption profile with a low power, chirped laser while measuring the transmitted intensity results in a time-domain readout of the accumulated RF signal spectrum. The resolution of the spectrum analyzer is limited only by the homogeneous linewidth of the rare earth ions ( 20 GHz.
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demonstration of a radio frequency spectrum analyser based on Spectral Hole Burning
Journal of Modern Optics, 2002Co-Authors: Ivan Lorgeré, Loïc Ménager, Jean-louis Le Gouët, Daniel Dolfi, V Lavielle, S Tonda, Jean-pierre HuignardAbstract:We demonstrate application of Spectral Hole Burning to the Spectral analysis of broad-band rf signals. In quite the same way as an acousto-optic spectrometer, the device operates on an optically carried rf signal and achieves angular separation of the signal Spectral components. An instantaneous bandwidth of 2.5 GHz has been achieved, with a power dynamic range of 35 dB, limited by the detector. Extension to greater than 10 GHz instantaneous bandwidth with greater than 1000 channels is consistent with the active material capabilities.
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Demonstration of a radio-frequency spectrum analyzer based on Spectral Hole Burning
Opt. Lett., 2001Co-Authors: Loïc Ménager, Jean-louis Le Gouët, Ivan Lorgeré, Daniel Dolfi, Jean-pierre HuignardAbstract:Spectral Hole-Burning (SHB) technology is considered for >10-GHz instantaneous bandwidth signal-processing applications. In this context we report on what is believed to be the first demonstration of a SHB microwave spectrometer. A set of gratings engraved in a SHB crystal is used to filter one sideband of the optically carried microwave signal. The setup is confined to narrow-bandwidth operation, over a 35-MHz-wide interval. The first findings confirm the validity of the architecture in terms of Spectral resolution, angular channel separation, and simultaneous detection of multiple Spectral lines.
D Bimberg - One of the best experts on this subject based on the ideXlab platform.
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lateral cavity Spectral Hole Burning in quantum dot lasers
Applied Physics Letters, 2002Co-Authors: D Ouyang, R Heitz, N N Ledentsov, S Bognar, R L Sellin, Ch Ribbat, D BimbergAbstract:Spectral Hole Burning effects are observed as strong Spectral intensity modulations in the emission spectra of broad and narrow stripe quantum-dot lasers with ridge waveguide. The modulation is attributed to lateral-cavity resonances Burning Holes in the inhomogeneously broadened Spectral gain profile of the quantum dots. Lateral cavity engineering is expected to be crucial for optimizing quantum-dot laser performance and for potential realizing of wavelength-stabilized devices.
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Spectral Hole Burning and carrier heating dynamics in quantum dot amplifiers comparison with bulk amplifiers
Physica Status Solidi B-basic Solid State Physics, 2001Co-Authors: Paola Borri, Wolfgang Werner Langbein, J M Hvam, F Heinrichsdorff, M H Mao, D BimbergAbstract:The ultrafast gain dynamics in an electrically pumped InAs/InGaAs/GaAs quantum-dot amplifier are measured at room temperature with femtosecond resolution, and compared with results on an InGaAsP bulk amplifier. The role of Spectral Hole Burning and carrier heating in the recovery of the gain compression is investigated. Reduced carrier heating for both gain and refractive index dynamics of the quantum-dot device is found, which is a promising prerequisite for high-speed applications.
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Spectral Hole Burning and carrier heating dynamics in ingaas quantum dot amplifiers
IEEE Journal of Selected Topics in Quantum Electronics, 2000Co-Authors: Paola Borri, Wolfgang Werner Langbein, J M Hvam, F Heinrichsdorff, M H Mao, D BimbergAbstract:The ultrafast gain and index dynamics in a set of InAs-InGaAs-GaAs quantum-dot (QD) amplifiers are measured at room temperature with femtosecond resolution. The role of Spectral Hole-Burning (SHB) and carrier heating (CH) in the recovery of gain compression is investigated in detail. An ultrafast recovery of the Spectral Hole within /spl sim/100 fs is measured, comparable to bulk and quantum-well amplifiers, which is contradicting a carrier relaxation bottleneck in electrically pumped QD devices. The CH dynamics in the QD is quantitatively compared with results on an InGaAsP bulk amplifier. Reduced CH for both gain and refractive index dynamics of the QD devices is found, which is a promising prerequisite for high-speed applications. This reduction is attributed to reduced free-carrier absorption-induced heating caused by the small carrier density necessary to provide amplification in these low-dimensional systems.
William R Babbitt - One of the best experts on this subject based on the ideXlab platform.
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optical decoherence and persistent Spectral Hole Burning in er3 linbo3
Journal of Luminescence, 2010Co-Authors: C W Thiel, R L Cone, R M Macfarlane, Thomas Bottger, Yongchen Sun, William R BabbittAbstract:Abstract Developing new resonant optical materials for spatial-Spectral holography and quantum information applications requires detailed knowledge of the decoherence and population relaxation dynamics for the quantum states involved in the optical transitions, motivating the need for fundamental material studies. We report recent progress in studying these properties in erbium-doped lithium niobate at liquid helium temperatures. The influence of temperature, applied magnetic fields, measurement timescale, and dopant concentration were probed using photon echo spectroscopy and time-resolved Spectral Hole Burning on the 1532 nm transition of Er 3+ :LiNbO 3 . Effects of Spectral diffusion due to interactions between Er 3+ ions and between the Er 3+ ion and 7 Li and 93 Nb nuclear spins in the host lattice were observed. In addition, long-lived persistent Spectral storage of seconds to minutes was observed due to non-equilibrium population redistribution among superhyperfine states.
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Spectral Hole Burning for wideband high resolution radio frequency spectrum analysis
Optics Letters, 2005Co-Authors: Friso Schlottau, Max Colice, Kelvin H Wagner, William R BabbittAbstract:We present experimental results for what is to our knowledge the first Spectral-Hole-Burning based rf spectrum analyzer to cover 10 GHz of rf analysis bandwidth. The rf signal of interest is modulated onto an optical carrier, and the resultant optical sidebands are burned into the inhomogeneously broadened absorption band of a Tm3+:YAG crystal. At the same time a second, frequency-swept laser reads out the absorption profile, which is a double-sideband replica of the rf spectrum, and thus the rf spectrum can be deduced after Spectral calibration of the nonlinear readout chirp. This initial demonstration shows Spectral analysis covering 10 GHz of bandwidth with >5500 Spectral channels and provides 43 dB of dynamic range.
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rf spectrum analysis in Spectral Hole Burning media
on Optical information systems, 2004Co-Authors: Max Colice, Ivan Lorgeré, Friso Schlottau, Kelvin H Wagner, Krishna R Mohan, William R Babbitt, Jean-louis Le GouëtAbstract:We propose a novel, wideband spectrum analyzer based on Spectral Hole Burning (SHB) technology. SHB crystals contain rare earth ions doped into a host lattice, and are cooled to cryogenic temperatures to allow sub-MHz Hole Burning linewidths. The signal spectrum is recorded in an SHB crystal by illuminating the crystal with an optical beam modulated by the RF signal of interest. The signal's Spectral components excite those rare earth ions whose resonance frequencies coincide with the Spectral component frequencies, engraving the RF spectrum into the crystal's absorption profile. Probing this altered absorption profile with a low power, chirped laser while measuring the transmitted intensity results in a time-domain readout of the accumulated RF signal spectrum. The resolution of the spectrum analyzer is limited only by the homogeneous linewidth of the rare earth ions ( 20 GHz.
Masayuki Nogami - One of the best experts on this subject based on the ideXlab platform.
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formation of sm2 ions and Spectral Hole Burning in x ray irradiated glasses
Journal of Physical Chemistry B, 2002Co-Authors: Masayuki Nogami, Kazuhiro SuzukiAbstract:Al2O3−SiO2 glasses were prepared for doping with Sm3+ ions using a sol−gel method, followed by X-ray irradiation, in which formation of the Sm2+ ions and persistent Spectral Hole Burning (PSHB) were investigated. The X-ray irradiation brought about Hole centers in the oxygen ions bound with Al3+ ions. And the released electrons are captured in the Sm3+ ions to form Sm2+ ions. The X-ray reduced Sm2+ ions are not so stable that they change into Sm3+ by heating at 200 to 300 °C. The Spectral Holes were burned in the 7F0→5D0 line of the Sm2+ ions, in which deep Holes could be burned within a short laser-irradiation period compared with that of the H2-gas heated glass. Hole spectra were stable up to room temperature, at which the Hole depth was ∼20% of the total fluorescence intensity. Bleaching at the low energy sites of the 7F0→5D0 transition was observed during irradiation with the laser. The results definitely reveal that the PSHB is formed by the electron transfer between the Sm2+ ions and the Hole center...
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Spectral Hole Burning of eu3 doped al2o3 sio2 glass prepared by melt quenching
Optics Communications, 2001Co-Authors: Masayuki Nogami, Takahiro Kawaguchi, Atsuo YasumoriAbstract:Abstract Persistent Spectral Hole Burning of Eu3+ ions was investigated using a glass prepared by the melt-quenching technique. The Eu2O3-doped Al2O3–SiO2 glass was melted at 2100°C and quenched using twin-rollers. The Eu3+ ions were accommodated in two different site distributions related to rich and poor phase in Al–O polyhedra in the glass network structure, some of which were reduced into Eu2+. The persistent Spectral Holes were burned in the excitation spectrum of the 7 F 0 → 5 D0 transition of Eu3+ at temperatures ranging from 8 K to room temperature. The depth and width were shallower and wider than those for the glass with same composition prepared by the sol–gel method.
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persistent Spectral Hole Burning in eu3 doped silicate glasses codoping al3 and p5 ions
Chemistry of Materials, 1998Co-Authors: Masayuki Nogami, Takehito Nagakura, Tomokatsu Hayakawa, Tomokazu SakaiAbstract:Eu3+-doped SiO2, Al2O3−SiO2, and P2O5−SiO2 glasses were prepared by a sol−gel method from metal alkoxides, and their persistent Spectral Hole Burning (PSHB) properties were investigated in relation...
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high temperature persistent Spectral Hole Burning of eu3 doped sio2 glass prepared by the sol gel process
Applied Physics Letters, 1997Co-Authors: Masayuki Nogami, Yoshihiro AbeAbstract:Persistent Spectral Hole Burning was observed at temperatures higher than 77 K in SiO2 glass doped with the Eu3+ ions. The Eu3+-doped SiO2 glass was prepared using the sol-gel process of Si(OC2H5)4 and EuCl3⋅6H2O. A persistent Spectral Hole was burned in the excitation spectrum of the 7F0→5D0 transition of Eu3+ using a Rhodamine 6G dye laser, of which the Hole width and depth were 1.6 cm−1 and ∼20% of the total intensity, respectively, at 77 K. Hole depth decreased with increasing temperature and disappeared above ∼130 K. A possible mechanism for the Hole Burning is related to the local structure around Eu3+ and the residual OH and H2O in the glass.
