The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Guillermo Carpintero - One of the best experts on this subject based on the ideXlab platform.
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on chip colliding pulse mode locked laser diode occp mlld using multimode interference reflectors
Optics Express, 2015Co-Authors: Carlos Gordon, Robinson Guzman, V Corral, X J M Leijtens, Guillermo CarpinteroAbstract:We report the achievement of colliding pulse mode-locked (CPM) regimes on a novel on-chip mode locked laser diode (OCCP-MLLD). The advantage of the resonator structure that we present is that the end-mirrors are defined through multimode interference reflectors (MIRs), which provide precise control of the cavity length avoiding the need for cleaved facets. This simplifies positioning the saturable absorber at the center of the resonator to achieve the colliding pulse mode-locked regime and double the repetition rate, reaching the millimeter wave frequency range. An additional advantage is that the pulsed output is delivered within the Photonic Integrated Circuit chip for further processing (i.e. modulation). We demonstrate a colliding pulse passive mode locked regime with pulse widths below a picosecond (Δτ = 0.64 ps), timing jitter σT = 75 fs and amplitude noise NAM = 0.012 dBc. The samples were fabricated in a generic InP foundry service through multi-project wafer (MPW) runs.
J. Martin Berglund - One of the best experts on this subject based on the ideXlab platform.
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Femtosecond two-photon photoassociation of hot magnesium atoms: A quantum dynamical study using thermal random phase wavefunctions
Journal of Chemical Physics, 2013Co-Authors: Saieswari Amaran, Leonid Rybak, Liat Levin, Michal Tomza, Robert Moszynski, Ronnie Kosloff, Zohar Amitay, Wojciech Skomorowski, Filip Pawłowski, J. Martin BerglundAbstract:Two-photon photoassociation of hot magnesium atoms by femtosecond laser pulses, creating electronically excited magnesium dimer molecules, is studied from first principles, combining ab initio quantum chemistry and molecular quantum dynamics. This theoretical framework allows for rationalizing the generation of molecular rovibrational coherence from thermally hot atoms [L. Rybak, S. Amaran, L. Levin, M. Tomza, R. Moszynski, R. Kosloff, C. P. Koch, and Z. Amitay, Phys. Rev. Lett. 107, 273001 (2011)]. Random phase thermal wavefunctions are employed to model the thermal ensemble of hot colliding atoms. Comparing two different choices of basis functions, random phase wavefunctions built from eigenstates are found to have the fastest convergence for the photoassociation yield. The interaction of the colliding atoms with a femtosecond laser pulse is modeled non-perturbatively to account for strong-field effects.
Carlos Gordon - One of the best experts on this subject based on the ideXlab platform.
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on chip colliding pulse mode locked laser diode occp mlld using multimode interference reflectors
Optics Express, 2015Co-Authors: Carlos Gordon, Robinson Guzman, V Corral, X J M Leijtens, Guillermo CarpinteroAbstract:We report the achievement of colliding pulse mode-locked (CPM) regimes on a novel on-chip mode locked laser diode (OCCP-MLLD). The advantage of the resonator structure that we present is that the end-mirrors are defined through multimode interference reflectors (MIRs), which provide precise control of the cavity length avoiding the need for cleaved facets. This simplifies positioning the saturable absorber at the center of the resonator to achieve the colliding pulse mode-locked regime and double the repetition rate, reaching the millimeter wave frequency range. An additional advantage is that the pulsed output is delivered within the Photonic Integrated Circuit chip for further processing (i.e. modulation). We demonstrate a colliding pulse passive mode locked regime with pulse widths below a picosecond (Δτ = 0.64 ps), timing jitter σT = 75 fs and amplitude noise NAM = 0.012 dBc. The samples were fabricated in a generic InP foundry service through multi-project wafer (MPW) runs.
Saieswari Amaran - One of the best experts on this subject based on the ideXlab platform.
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Femtosecond two-photon photoassociation of hot magnesium atoms: A quantum dynamical study using thermal random phase wavefunctions
Journal of Chemical Physics, 2013Co-Authors: Saieswari Amaran, Leonid Rybak, Liat Levin, Michal Tomza, Robert Moszynski, Ronnie Kosloff, Zohar Amitay, Wojciech Skomorowski, Filip Pawłowski, J. Martin BerglundAbstract:Two-photon photoassociation of hot magnesium atoms by femtosecond laser pulses, creating electronically excited magnesium dimer molecules, is studied from first principles, combining ab initio quantum chemistry and molecular quantum dynamics. This theoretical framework allows for rationalizing the generation of molecular rovibrational coherence from thermally hot atoms [L. Rybak, S. Amaran, L. Levin, M. Tomza, R. Moszynski, R. Kosloff, C. P. Koch, and Z. Amitay, Phys. Rev. Lett. 107, 273001 (2011)]. Random phase thermal wavefunctions are employed to model the thermal ensemble of hot colliding atoms. Comparing two different choices of basis functions, random phase wavefunctions built from eigenstates are found to have the fastest convergence for the photoassociation yield. The interaction of the colliding atoms with a femtosecond laser pulse is modeled non-perturbatively to account for strong-field effects.
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femtosecond two photon photoassociation of hot magnesium atoms a quantum dynamical study using thermal random phase wavefunctions
arXiv: Quantum Physics, 2012Co-Authors: Saieswari Amaran, Leonid Rybak, Liat Levin, Michal Tomza, Robert Moszynski, Ronnie Kosloff, Zohar Amitay, Wojciech Skomorowski, Filip Pawlowski, Martin J BerglundAbstract:Two-photon photoassociation of hot magnesium atoms by femtosecond laser pulses, creating electronically excited magnesium dimer molecules, is studied from first principles, combining \textit{ab initio} quantum chemistry and molecular quantum dynamics. This theoretical framework allows for rationalizing the generation of molecular rovibrational coherence from thermally hot atoms [L. Rybak \textit{et al.}, Phys. Rev. Lett. {\bf 107}, 273001 (2011)]. Random phase thermal wave functions are employed to model the thermal ensemble of hot colliding atoms. Comparing two different choices of basis functions, random phase wavefunctions built from eigenstates are found to have the fastest convergence for the photoassociation yield. The interaction of the colliding atoms with a femtosecond laser pulse is modeled non-perturbatively to account for strong-field effects.
Douglas N C Lin - One of the best experts on this subject based on the ideXlab platform.
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globular cluster formation from colliding substructure
The Astrophysical Journal, 2020Co-Authors: Piero Madau, Alessandro Lupi, Juerg Diemand, Andreas Burkert, Douglas N C LinAbstract:We investigate a scenario where the formation of Globular Clusters (GCs) is triggered by high-speed collisions between infalling atomic-cooling subhalos during the assembly of the main galaxy host, a special dynamical mode of star formation that operates at high gas pressures and is intimately tied to LCDM hierarchical galaxy assembly. The proposed mechanism would give origin to "naked" globulars, as colliding dark matter subhalos and their stars will simply pass through one another while the warm gas within them clashes at highly supersonic speed and decouples from the collisionless component, in a process reminiscent of the Bullet galaxy cluster. We find that the resulting shock-compressed layer cools on a timescale that is typically shorter than the crossing time, first by atomic line emission and then via fine-structure metal-line emission, and is subject to gravitational instability and fragmentation. Through a combination of kinetic theory approximation and high-resolution $N$-body simulations, we show that this model may produce: (a) a GC number-halo mass relation that is linear down to dwarf galaxy scales and agrees with the trend observed over five orders of magnitude in galaxy mass; (b) a population of old globulars with a median age of 12 Gyr and an age spread similar to that observed; (c) a spatial distribution that is biased relative to the overall mass profile of the host; and (d) a bimodal metallicity distribution with a spread similar to that observed in massive galaxies.