Femtosecond dynamics of cluster expansion

POSTER

Abstract

Noble gas clusters irradiated by intense ultrafast laser expand quickly and become typical plasma in picosecond time scale. During the expansion, the clustered plasma demonstrates unique optical properties such as strong absorption and positive contribution to the refractive index. Here we studied cluster expansion dynamics by fs-time-resolved refractive index and absorption measurements in cluster gas jets after ionization and heating by an intense pump pulse. The refractive index measured by frequency domain interferometry (FDI) shows the transient positive peak of refractive index due to clustered plasma. By separating it from the negative contribution of the monomer plasma, we are able to determine the cluster fraction. The absorption measured by a delayed probe shows the contribution from clusters of various sizes. The plasma resonances in the cluster explain the enhancement of the absorption in our isothermal expanding cluster model. The cluster size distribution can be determined. A complete understanding of the femtosecond dynamics of cluster expansion is essential in the accurate interpretation and control of laser-cluster experiments such as phase-matched harmonic generation in cluster medium.

Authors

  • Xiaohui Gao

    University of Texas at Austin

  • Sacha Kopp

    Texas Lutheran, Texas Lutheran University, Bastrop ISD, Lego Education, LEGO Education, South Texas Chapter, Health Physics Society, Waxahachie Early College High School, Navarro College, and Texas A\&M Commerce, PTRA/AAPT, National Instruments, Department of Physics, University of Texas at Austin, Texas A&M University - Commerce, University of Dallas, Austin Community College, Angelo State University, K-12 Science Consultant Birdville ISD, Energy Institute, University of Texas at Austin, Southern Univertisy Baton Rouge, Univ. of Arkansas, Univ. of Central Florida, JQI, NIST and Univ. of Maryland, UT Austin, Center for Ultrafast Optical Science, University of Michigan, Lawrence Berkeley National Laboratory, University of Texas at Austin, Lockheed Martin, NASA, South Plains College, LBNL-ALS, Berkeley, Denison U., Granville, U. of Nevada, Reno, Justus-Liebig-Universitat, Giessen, Western Michigan U., Kalamazoo, University of Texas at Austin, Department of Physics, Institute for Applied Physics, University of Muenster

  • Sacha Kopp

    Texas Lutheran, Texas Lutheran University, Bastrop ISD, Lego Education, LEGO Education, South Texas Chapter, Health Physics Society, Waxahachie Early College High School, Navarro College, and Texas A\&M Commerce, PTRA/AAPT, National Instruments, Department of Physics, University of Texas at Austin, Texas A&M University - Commerce, University of Dallas, Austin Community College, Angelo State University, K-12 Science Consultant Birdville ISD, Energy Institute, University of Texas at Austin, Southern Univertisy Baton Rouge, Univ. of Arkansas, Univ. of Central Florida, JQI, NIST and Univ. of Maryland, UT Austin, Center for Ultrafast Optical Science, University of Michigan, Lawrence Berkeley National Laboratory, University of Texas at Austin, Lockheed Martin, NASA, South Plains College, LBNL-ALS, Berkeley, Denison U., Granville, U. of Nevada, Reno, Justus-Liebig-Universitat, Giessen, Western Michigan U., Kalamazoo, University of Texas at Austin, Department of Physics, Institute for Applied Physics, University of Muenster

  • Sacha Kopp

    Texas Lutheran, Texas Lutheran University, Bastrop ISD, Lego Education, LEGO Education, South Texas Chapter, Health Physics Society, Waxahachie Early College High School, Navarro College, and Texas A\&M Commerce, PTRA/AAPT, National Instruments, Department of Physics, University of Texas at Austin, Texas A&M University - Commerce, University of Dallas, Austin Community College, Angelo State University, K-12 Science Consultant Birdville ISD, Energy Institute, University of Texas at Austin, Southern Univertisy Baton Rouge, Univ. of Arkansas, Univ. of Central Florida, JQI, NIST and Univ. of Maryland, UT Austin, Center for Ultrafast Optical Science, University of Michigan, Lawrence Berkeley National Laboratory, University of Texas at Austin, Lockheed Martin, NASA, South Plains College, LBNL-ALS, Berkeley, Denison U., Granville, U. of Nevada, Reno, Justus-Liebig-Universitat, Giessen, Western Michigan U., Kalamazoo, University of Texas at Austin, Department of Physics, Institute for Applied Physics, University of Muenster

  • Sacha Kopp

    Texas Lutheran, Texas Lutheran University, Bastrop ISD, Lego Education, LEGO Education, South Texas Chapter, Health Physics Society, Waxahachie Early College High School, Navarro College, and Texas A\&M Commerce, PTRA/AAPT, National Instruments, Department of Physics, University of Texas at Austin, Texas A&M University - Commerce, University of Dallas, Austin Community College, Angelo State University, K-12 Science Consultant Birdville ISD, Energy Institute, University of Texas at Austin, Southern Univertisy Baton Rouge, Univ. of Arkansas, Univ. of Central Florida, JQI, NIST and Univ. of Maryland, UT Austin, Center for Ultrafast Optical Science, University of Michigan, Lawrence Berkeley National Laboratory, University of Texas at Austin, Lockheed Martin, NASA, South Plains College, LBNL-ALS, Berkeley, Denison U., Granville, U. of Nevada, Reno, Justus-Liebig-Universitat, Giessen, Western Michigan U., Kalamazoo, University of Texas at Austin, Department of Physics, Institute for Applied Physics, University of Muenster

  • Sacha Kopp

    Texas Lutheran, Texas Lutheran University, Bastrop ISD, Lego Education, LEGO Education, South Texas Chapter, Health Physics Society, Waxahachie Early College High School, Navarro College, and Texas A\&M Commerce, PTRA/AAPT, National Instruments, Department of Physics, University of Texas at Austin, Texas A&M University - Commerce, University of Dallas, Austin Community College, Angelo State University, K-12 Science Consultant Birdville ISD, Energy Institute, University of Texas at Austin, Southern Univertisy Baton Rouge, Univ. of Arkansas, Univ. of Central Florida, JQI, NIST and Univ. of Maryland, UT Austin, Center for Ultrafast Optical Science, University of Michigan, Lawrence Berkeley National Laboratory, University of Texas at Austin, Lockheed Martin, NASA, South Plains College, LBNL-ALS, Berkeley, Denison U., Granville, U. of Nevada, Reno, Justus-Liebig-Universitat, Giessen, Western Michigan U., Kalamazoo, University of Texas at Austin, Department of Physics, Institute for Applied Physics, University of Muenster

  • Sacha Kopp

    Texas Lutheran, Texas Lutheran University, Bastrop ISD, Lego Education, LEGO Education, South Texas Chapter, Health Physics Society, Waxahachie Early College High School, Navarro College, and Texas A\&M Commerce, PTRA/AAPT, National Instruments, Department of Physics, University of Texas at Austin, Texas A&M University - Commerce, University of Dallas, Austin Community College, Angelo State University, K-12 Science Consultant Birdville ISD, Energy Institute, University of Texas at Austin, Southern Univertisy Baton Rouge, Univ. of Arkansas, Univ. of Central Florida, JQI, NIST and Univ. of Maryland, UT Austin, Center for Ultrafast Optical Science, University of Michigan, Lawrence Berkeley National Laboratory, University of Texas at Austin, Lockheed Martin, NASA, South Plains College, LBNL-ALS, Berkeley, Denison U., Granville, U. of Nevada, Reno, Justus-Liebig-Universitat, Giessen, Western Michigan U., Kalamazoo, University of Texas at Austin, Department of Physics, Institute for Applied Physics, University of Muenster