Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Bi-directional description of amplified spontaneous emission induced by three-photon absorption
KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.ORCID-id: 0000-0003-1269-8760
KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
Visa övriga samt affilieringar
2005 (Engelska)Ingår i: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, E-ISSN 1520-8540, Vol. 22, nr 2, s. 385-393Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

 A semiclassical dynamic theory of the nonlinear propagation of a few interacting intense light pulses is applied to study the nonlinear counterpropagation of amplified spontaneous emission (ASE) induced by three-photon absorption of short intense laser pulses in a chromophore solution. Several important results from the modeling are reached for the ASE process developing in the regime of strong saturation. Accounting for ASE in both forward and backward directions with respect to the pump pulse results in a smaller efficiency of nonlinear conversion for the forward ASE compared with the case in which forward emission is considered alone, something that results from the partial repump of the absorbed energy to the backward ASE component; the overall efficiency is nevertheless higher than for the forward emission considered alone. The efficiency of nonlinear conversion of the pump energy to the counterpropagating ASE pulses is strongly dependent on the concentration of active molecules so that a particular combination of concentration versus cell length optimizes the conversion coefficient. Under certain specified conditions, the ASE effect is found to be oscillatory; the origin of oscillations is dynamical competition between stimulated emission and off-resonant absorption. This result can be considered one of the possible explanations of the temporal fluctuations of the forward ASE pulse [Nature 415, 767 (2002)].

Ort, förlag, år, upplaga, sidor
2005. Vol. 22, nr 2, s. 385-393
Nyckelord [en]
Laser pulses, Light absorption, Light propagation, Mathematical models, Maxwell equations, Optical frequency conversion, Optical materials, Optical pumping, Oscillations, Photons, Spontaneous emission, Wave equations
Nationell ämneskategori
Fysik
Identifikatorer
URN: urn:nbn:se:kth:diva-5486DOI: 10.1364/JOSAB.22.000385ISI: 000226967800012Scopus ID: 2-s2.0-15044350805OAI: oai:DiVA.org:kth-5486DiVA, id: diva2:9869
Anmärkning
QC 20100901Tillgänglig från: 2006-03-15 Skapad: 2006-03-15 Senast uppdaterad: 2017-11-21Bibliografiskt granskad
Ingår i avhandling
1. Pulse Propagation in Nonlinear Media and Photonic Crystals
Öppna denna publikation i ny flik eller fönster >>Pulse Propagation in Nonlinear Media and Photonic Crystals
2006 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

The present thesis is devoted to theoretical studies of pulse propagation of light through linear and nonlinear media, and of light-induced nuclear dynamics.

The first part of the thesis addresses propagation of light pulses in linear periodical media - photonic crystals. The main accent was put on studies of the angular properties of two qualitatively different types of photonic crystals: holographic photonic crystals, and impurity band based photonic crystals. The anisotropy of band structure, group velocity and pulse delay with respect to the light polarization are analyzed.

In the second part of the thesis a strict theory of nonlinear propagation of a few strong interacting light beams is presented. The key idea of this approach is a self-consistent solution of the nonlinear wave equation and the density matrix equations of the material. This technique is applied to studies of dynamics of cavityless lasing generated by ultra-fast multi-photon excitation. It is shown that interaction of co- and counter-propagating pulses of amplified spontaneous emission (ASE) affects the dynamics and efficiency of nonlinear conversion. Our dynamical theory allows to explain the asymmetric spectral properties of the forward and backward ASE pulses, which were observed in recent experiment with different dye molecules. It is shown that the ASE spectral profile changes drastically when the pump intensity approaches the threshold level. The effect of the temporal self-pulsation of ASE is studied in detail.

The third part of the thesis is devoted to light-induced nuclear dynamics. Time- and frequency-resolved X-ray spectroscopy of molecules driven by strong and coherent infrared (IR) pulses shows that the phase of the IR field strongly influences the trajectory of the nuclear wave packet, and hence, the X-ray spectrum. Such a dependence arises due to the interference of one (X-ray) and two-photon (X-ray + IR) excitation channels. The phase of the light influences the dynamics also when the Rabi frequency approaches the vibrational frequency, breaking down the rotating-wave approximation. The probe X-ray spectra are also sensitive to the delay time, the duration, and the shape of the pulses. The evolution of the nuclear wave packets in the dissociative core-excited state affects the dynamics of resonant Auger scattering from fixed-in-space molecules. One of the important dynamical effects is the atomic-like resonance which experiences electronic Doppler shift. We predict that the scattering of the Auger electrons by nearby atoms leads to new Doppler shifted resonances. These extra resonances show sharp maxima in the bond directions, which makes them very promising as probes for local molecular structure using energy and angular resolved electron-ion coincidence techniques. Our theory provides prediction of several new effects, but also results that are in good agreement with the available experimental data.

Ort, förlag, år, upplaga, sidor
Stockholm: KTH, 2006. s. x, 49
Nyckelord
Photonic Crystals, Nonlinear optics, X-ray spectroscopy
Nationell ämneskategori
Teoretisk kemi
Identifikatorer
urn:nbn:se:kth:diva-3886 (URN)91-7178-275-3 (ISBN)
Disputation
2006-03-31, FB42, AlbaNova, Roslagstullsbaken 21, Stockholm, 10:00
Opponent
Handledare
Anmärkning
QC 20100906Tillgänglig från: 2006-03-15 Skapad: 2006-03-15 Senast uppdaterad: 2011-11-23Bibliografiskt granskad
2. Pulse propagation in photonic crystals and nonlinear media
Öppna denna publikation i ny flik eller fönster >>Pulse propagation in photonic crystals and nonlinear media
2005 (Engelska)Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

The present thesis is devoted to theoretical studies of light pulse propagation through different linear and nonlinear media. One dimensional holographic photonic crystals and one dimensional impurity band based photonic crystals are investigated as linear media. The effects of angular dependence of the band structures and pulse delay with respect to the light polarization are analyzed. A strict theory of nonlinear propagation of a few strong interacting light beams is presented and applied in the field of nonlinear optics. The key idea of this approach is a self-consistent solution of the nonlinear wave equation and the density matrix equations of the material beyond the so-called rotating wave approximation. The results of numerical studies led to a successful interpretation of recent experimental data [Nature, 415:767, 2002]. A theoretical study of the NO molecule by means of two-color infrared -- X-ray pump probe spectroscopy is presented. It was found that the phase of the infrared field strongly influences the trajectory of the nuclear wave packet, and hence, the X-ray spectrum. The dependence of the X-ray spectra on the delay time, the duration and the shape of the pulses are studied.

Ort, förlag, år, upplaga, sidor
Stockholm: KTH, 2005. s. iii, 32
Nyckelord
Theoretical chemistry, Teoretisk kemi
Nationell ämneskategori
Teoretisk kemi
Identifikatorer
urn:nbn:se:kth:diva-351 (URN)91-7178-023-8 (ISBN)
Presentation
2005-05-24, Sal FB42, AlbaNova, Roslagstullssbacken 21, Stockholm, 10:00
Handledare
Anmärkning
QC 20101207Tillgänglig från: 2005-08-01 Skapad: 2005-08-01 Senast uppdaterad: 2011-11-23Bibliografiskt granskad

Open Access i DiVA

Fulltext saknas i DiVA

Övriga länkar

Förlagets fulltextScopus

Personposter BETA

Kimberg, ViktorÅgren, Hans

Sök vidare i DiVA

Av författaren/redaktören
Kimberg, ViktorPolyutov, SergeyGelmukhanov, FarisÅgren, Hans
Av organisationen
Teoretisk kemi
I samma tidskrift
Journal of the Optical Society of America. B, Optical physics
Fysik

Sök vidare utanför DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetricpoäng

doi
urn-nbn
Totalt: 323 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf