Bio

Andrew J. Howard received his B.S. in Optics from the University of Rochester in 2019. During his time at Rochester, he served as a Research Assistant in the ultrafast group at the Laboratory for Laser Energetics. He was awarded the Charles L. Newton Prize for his work. In late 2019, Howard enrolled in the Applied Physics Ph.D. program at Stanford University and was named the Albion Walter Hewlett Fellow. Here he studies experimental strong-field physics and ultrafast laser-driven molecular dynamics. He currently specializes in 3D fragment-momentum imaging, in which the three-dimensional momentum of molecular fragments produced during the interaction between a laser and a molecule yields valuable information about femtosecond molecular processes and light-matter interactions.

Honors & Awards

  • Albion Walter Hewlett Fellowship, Stanford University (2019)
  • Charles L. Newton Prize, University of Rochester (2019)
  • Robert L. Wells Prize, University of Rochester (2019)

Education & Certifications

  • B.S., The Institute of Optics, University of Rochester, Optics (2019)
  • Minor, University of Rochester, Italian (2019)

Contact

  • Academic
    ahow@stanford.edu
    University - Student Department: Applied Physics Position: Graduate

Additional Info

  • Mail Code: 2010

All Publications

  • Strong-field ionization of water: Nuclear dynamics revealed by varying the pulse duration PHYSICAL REVIEW A Howard, A. J., Cheng, C., Forbes, R., McCracken, G. A., Mills, W. H., Makhija, Spanner, M., Weinacht, T., Bucksbaum, P. H. 2021; 103 (4)

    View details for DOI 10.1103/PhysRevA.103.043120

    View details for Web of Science ID 000646165800005

  • Photon Acceleration in a Flying Focus PHYSICAL REVIEW LETTERS Howard, A. J., Turnbull, D., Davies, A. S., Franke, P., Froula, D. H., Palastro, J. P. 2019; 123 (12): 124801

    Abstract

    A high-intensity laser pulse propagating through a medium triggers an ionization front that can accelerate and frequency upshift the photons of a second pulse. The maximum upshift is ultimately limited by the accelerated photons outpacing the ionization front or the ionizing pulse refracting from the plasma. Here, we apply the flying focus-a moving focal point resulting from a chirped laser pulse focused by a chromatic lens-to overcome these limitations. Theory and simulations demonstrate that the ionization front produced by a flying focus can frequency upshift an ultrashort optical pulse to the extreme ultraviolet over a centimeter of propagation. An analytic model of the upshift predicts that this scheme could be scaled to a novel tabletop source of spatially coherent x rays.

    View details for DOI 10.1103/PhysRevLett.123.124801

    View details for Web of Science ID 000487743500009

    View details for PubMedID 31633954

  • Implementation of a Wollaston interferometry diagnostic on OMEGA EP Howard, A., Haberberger, D., Boni, R., Brown, R., Froula, D. H. AMER INST PHYSICS. 2018: 10B107

    Abstract

    A Wollaston interferometer is presented for use in measuring the electron density of plasma plumes created in experiments on the OMEGA EP laser system. The diagnostic is installed as an additional arm on the 4ω probe system, a suite of diagnostics that share a 10 ps pulse of 263 nm laser light captured by an imaging system at f/4. The interferometer utilizes a Wollaston prism to create two angularly separated beams from a single input probe beam, split at any angle between 0° and 90°. This configuration is implemented uniquely such that fringe spacing may be altered independently of field of view, magnification, and imaging resolution, from a range of 17 to 76 μm/fringe. The region of overlap between the two beams forms a total field of view of approximately 1.2 × 1.6 mm at the target chamber center with an imaging resolution of 5 μm. Using this configuration, here it is shown that plasma density may be accurately characterized over a range of 3 × 1018-1 × 1020 cm-3.

    View details for DOI 10.1063/1.5036956

    View details for Web of Science ID 000449144500008

    View details for PubMedID 30399724

  • Time-resolved site-selective imaging of predissociation and charge transfer dynamics: the CH3I B-band JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS Forbes, R., Allum, F., Bari, S., Boll, R., Borne, K., Brouard, M., Bucksbaum, P. H., Ekanayake, N., Erk, B., Howard, A. J., Johnsson, P., Lee, J. L., Manschwetus, B., Mason, R., Passow, C., Peschel, J., Rivas, D. E., Roerig, A., Rouzee, A., Vallance, C., Ziaee, F., Rolles, D., Burt, M. 2020; 53 (22)

    View details for DOI 10.1088/1361-6455/abb1fd

    View details for Web of Science ID 000581546500001

  • Momentum-resolved above-threshold ionization of deuterated water PHYSICAL REVIEW A Cheng, C., Forbes, R., Howard, A. J., Spanner, M., Bucksbaum, P. H., Weinacht, T. 2020; 102 (5)

    View details for DOI 10.1103/PhysRevA.102.052813

    View details for Web of Science ID 000589620200002

  • Flying focus: Spatial and temporal control of intensity for laser-based applications PHYSICS OF PLASMAS Froula, D. H., Palastro, J. P., Turnbull, D., Davies, A., Nguyen, L., Howard, A., Ramsey, D., Franke, P., Bahk, S., Begishev, I. A., Boni, R., Bromage, J., Bucht, S., Follett, R. K., Haberberger, D., Jenkins, G. W., Katz, J., Kessler, T. J., Shaw, J. L., Vieira, J. 2019; 26 (3)

    View details for DOI 10.1063/1.5086308

    View details for Web of Science ID 000462916300011