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Welcome to the University of Delaware's Ultrafast Wiki

About Ultrafast Science at UD The broad field of ultrafast science utilizes femtosecond ($10^{-15}$ seconds) optical pulses to study a variety of physical phenomena, ranging from quantum processes to the generation of extreme light fields. The University of Delaware has developed a research core in the field of ultrafast science. This research core, which spans over three departments, currently consists of five faculty members and over 15 graduate students, with research interests ranging from studying electron dynamics in quantum systems to ultrastrong light-matter interactions. Publications Highlight B. Fang, O. Cohen, J. B. Moreno, and V. O. Lorenz, "State engineering of photon pairs produced through dual-pump spontaneous four-wave mixing" Opt. Express 21 2707-2717 (2013) In this work we study theoretically the joint spectral properties of photon-pairs produced through spontaneous four-wave mixing (SFWM) with two spectrally distinct pump pulses in optical fibers. We show that, due to the group velocity difference between the pulses, the signature of the interaction can be significantly different from spontaneous parametric down-conversion or SFWM with a single pump pulse. Y. Gao and M.F. DeCamp "Generation of acoustic pulses from a photo-acoustic transducer measured by time-resolved x-ray diffraction" Applied Physics Letters 100 191903 (2012) This work studied the generation of picosecond acoustic pulses generated by ultrafast optical excitation of a photo-acoustic transducer using time-resolved x-ray diffraction. The resulting pump-probe spectra reveal that the spatiotemporal structure of the acoustic pulse is bipolar with acoustic wavevectors up to inverse of the film thickness. S. E. Economou, J. I. Climente, A. Badolato, A. S. Bracker, D. Gammon, M. F. Doty "Scalable qubit architecture based on holes in quantum dot molecules" Physical Review B, 86 085319 (2012) Spins confined in quantum dots are a leading candidate for solid-state quantum bits that can be coherently controlled by optical pulses. The use of hole spins allows the suppression of decoherence via hyperfine interactions and enables coherent spin rotations using Raman transitions mediated by a hole-spin-mixed optically excited state. Because the spin mixing is present only in the optically excited state, dephasing and decoherence are strongly suppressed in the ground states that define the qubits and nondestructive readout is possible. We present the qubit and device designs and analyze the wavelength tunability and fidelity of gate operations that can be implemented using this strategy. We then present experimental and theoretical progress toward implementing this design.

News 4/4/2013 Congratulations to Yuan Gao on the successful defense of his thesis, "Probing and Reconstructing Transient One-Dimensional Acoustic Strains using Time-Resolved X-Ray Diffraction"! 5/10/2013 Congratulations to Matthew Doty and Matthew DeCamp on their successful promotion to Associate Professor Upcoming Ultrafast Talks Matthew DeCamp, Department of Physics and Astronomy "Ultrafast spectroscopy across the electromagnetic spectrum" Department of Physics and Astronomy Colloquium September 12, 2012 4pm Gore 104 Noureddine Melikechi, Delaware State University “Detection and classification of disease biomarkers in complex media using laser induced breakdown spectroscopy: the case of epithelial ovarian cancer” Mechanical Engineering Seminar October 24, 2012 10 AM Brown Lab 219