Office: S2 154
Phone: 607 777 4362
Dr. Bonggu Shim received his Ph.D. in Physics from the University of Texas at Austin in 2006 and B.S. in physics from Seoul National University, South Korea in 1997. He joined our department in August 2012.
He studies nonlinear interactions with matter using high-power, ultrashort (femtosecond, 10-15 s) laser pulses.
1) Laser filamentation
Laser filamentation occurs when self-focusing due to the intensity-dependent refractive index is balanced by plasma defocusing, resulting in laser beam confinement over a long distance (even a few km). It is important with its applications to remote sensing, lightning guiding, terahertz radiation, and harmonic generation. Dr. Shim performed experiments on controlling interactions between multiple filaments and also carried out numerical (C/C++) simulations of nonlinear Schrödinger and envelope equations in nonlinear media at Cornell University.
2) High-order harmonic generation
Dr. Shim worked on high-order harmonic generation which can produce coherent, collimated radiations from ultraviolet to soft x-ray wavelengths. He achieved the first time-resolved harmonic generation from atomic argon clusters by demonstrating two cluster-based mechanisms: 1) nonlinear Mie resonance in each exploding cluster and 2) phase-matching in an argon gas jet which is composed of monomer plasmas and ionized clusters. He also worked on characterizing the cluster/monomer ratio in a high-pressure gas jet using the frequency-domain interferometry technique.
3) High-power laser construction
Dr. Shim played a leading role in constructing a multi-terawatt (300 mJ energy, 100 femtosecond) table-top Ti:Sapphire laser system for his Ph. D. work at the University of Texas at Austin. He was actively involved in modeling, designing, and constructing a Kerr-lens mode-locked oscillator, a pulse stretcher, a regenerative amplifier, multi-pass amplifiers, and a pulse compressor. The terawatt laser was successfully used for his dissertation work: high-order harmonic generation from atomic clusters.
Other research areas in which he is interested include nonlinear optics in hollow-core photonic band crystal fibers and frequency comb generation in micro-ring resonators.
T. Popmintchev, M.Chen, D. Popmintchev, P. Arpin, S. Ališauskas, G. Andriukaitis, T. Balčiunas, O. Mücke, A. Pugzlys, A. Baltuška, B. Shim, S. E. Schrauth, A. Gaeta, C. Hernández-García, L. Plaja, A. Becker, A. Jaron-Becker, M. Murnane, and H. Kapteyn, "Bright coherent ultrahigh harmonics in the keV x-ray regime from mid- infrared femtosecond lasers," Science 336, 1287 (2012) .
B. Shim, S. E. Schrauth, A. L. Gaeta, M. Klein, and G. Fibich, "Loss-of-phase of collapsing beams," Physical Review Letters 108, 043902 (2012).
B. Shim, G. Hays, R. Zgadzaj, T. Ditmire, and M. C. Downer, "Enhanced harmonic generation from expanding clusters," Physical Review Letters 98, 123902 (2007).
Last Updated: 9/23/12