Optical third-harmonic generation using ultrashort laser pulses

Journal Article · Wed Jun 15 04:00:00 EDT 2005 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.71.061802· OSTI ID:20717857

Stoker, D; Keto, J W ^[1]; Becker, M F ^[2]

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1. Department of Physics, University of Texas at Austin, 1 University Station C1600, Austin, Texas 78712-0264 (United States)
2. Center for Nano and Molecular Science and Technology and Texas Materials Institute, University of Texas at Austin, Building ETC, Room 8.102, Campus Mail Code C2201, Austin, Texas 78712-1063 (United States)

To better predict optical third-harmonic generation (THG) in transparent dielectrics, we model a typical ultrashort pulsed Gaussian beam, including both group velocity mismatch and phase mismatch of the fundamental and harmonic fields. We find that competition between the group velocity mismatch and phase mismatch leads to third-harmonic generation that is sensitive only to interfaces. In this case, the spatial resolution is determined by the group velocity walk-off length. THG of modern femtosecond lasers in optical solids is a bulk process, without a surface susceptibility, but bears the signature of a surface enhancement effect in z-scan measurements. We demonstrate the accuracy of the model, by showing the agreement between the predicted spectral intensity and the measured third-harmonic spectrum from a thin sapphire crystal.

• OSTI ID: 20717857
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 6 Vol. 71; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ACCURACY
CRYSTALS
DIELECTRIC MATERIALS
HARMONIC GENERATION
INTERFACES
LASER RADIATION
PULSES
SAPPHIRE
SOLIDS
SPATIAL RESOLUTION
VELOCITY