Publications

    C. B. Schaffer. 1999. “Non-perturbative up-conversion techniques: Ultrafast meets X-rays.” In Ultrafast Dynamics of Quantum Systems: Physical Processes and Spectroscopic Techniques, edited by B. Di Bartolo, Pp. 611–623. Plenum Press. Publisher's VersionAbstract
    Femtosecond laser pulses are now available from the ultraviolet (200 nm) all the way to the mid-infrared (12 m) in compact (often commercially available) systems. This tunability is achieved through perturbative nonlinear optical wavelength conversion techniques in crystals. To reach further into the ultraviolet and Xray regions of the spectrum, a new set of techniques becomes necessary. In this paper, we will review some of these nonperturbative nonlinear optical methods. Specifically, we will consider the high harmonic generation process in detail, and go through the essentials of the semi-classical theory. Next, we will review a new technique, based on Thomson scattering, which has produced 0.4-Angstrom, 300-fs radiation. Finally we will consider means of measuring femtosecond pulses in this short wavelength regime.
    R. J. Finlay and E. Mazur. 1998. “Femtosecond dynamics of molecular reactions at metal surfaces.” In Ultrafast Dynamics of Quantum Systems: Physical Processes and Spectroscopic Techniques, edited by B. Di Bartolo, Pp. 87–142. Plenum Press. Publisher's VersionAbstract
    These lectures are an introduction to current research into photo-induced chemical reactions at metal surfaces. After an introduction to some qualitative quantum mechanics, we discuss the electronic and optical properties of metals, beginning from an introductory level. The Drude model is described in detail and then optical properties of matter are developed more completely by introducing band structures. The physics governing adsorption of reactants at a metal surface and other fundamental concepts in surface science are introduced. We describe the interaction with a subpicosecond laser pulse with a metal surface in preparation for discussion of some recent photochemistry experiments using subpicosecond laser pulses. The experiments address the nature of the photo-excited electrons that are responsible for chemical reaction of the adsorbates.
    R. J. Finlay, T. Her, C. Wu, and E. Mazur. 1997. “Surface femtochemistry of oxygen and coadsorbates on Pt(111).” In Femtochemistry and Femtobiology: Ultrafast Reaction Dynamics at Atomic-Scale Resolution, edited by Villy Sundstrm, Pp. 629–659. Imperial College Press. Publisher's VersionAbstract
    We review the photoprocesses of oxygen on Pt(111), both with and without coadsorbates, and recent progress in describing these processes. We present new data that address the chemical pathway to formation of CO2 in CO/O2/Pt(111) induced by subpicosecond laser pulses. The data show conclusively that the O2 desorbs molecularly. We also find that if the CO reacts by an atomic pathway then the capture of oxygen atoms by the CO is highly efficient; if it reacts by a molecular pathway then the oxygen atoms in the transition state are inequivalent.
    E. Mazur. 1997. “Peer Instruction: Getting Students to Think in Class.” In The Changing Role of Physics Departments in Modern Universities, Part Two: Sample Classes, edited by Edward F. Redish and John S. Rigden, Pp. 981–988. American Institute of Physics. Publisher's VersionAbstract
    No abstract available. This paper, part of the proceedings for the International Conference on Undergraduate Physics Education held in College Park, Maryland in August 1996, is a reprint of Chapter 2 of "Peer Instruction: A User's Manual" by Eric Mazur (Prentice Hall, 1997). The chapter is available separately for downloading.
    E. Mazur. 1997. “Understanding or memorization: Are we teaching the right thing.” In Conference on the Introductory Physics Course on the occasion of the retirement of Robert Resnick, edited by Jack Wilson, Pp. 113–124. Wiley. Publisher's VersionAbstract
    When people I meet ask me what I do for a living and I tell them I am a physicist, I frequently hear horror stories about high school or college level physics – almost to the point of making me feel embarrassed about being a physicist! This general sense of frustration with introductory physics (mechanics, electricity and magnetism) is widespread among non-physics majors who are required to take physics courses. Even physics majors are frequently dissatisfied with their introductory courses and a large fraction of students initially interested in physics end up majoring in a different field. Frustration with introductory physics courses has been commented on since the days of Maxwell and has recently been publicized by Sheila Tobias. Tobias asked a number of graduate students in the humanities and social sciences to audit physics courses and describe their complaints. One may be tempted to brush off complaints by non-physics majors as coming from students who are ipso facto not interested in physics. Most of these students, however, are not complaining about other required courses outside their major field
    E. N. Glezer, M. Milosavljevic, L. Huang, R. J. Finlay, T. Her, J. Paul Callan, and E. Mazur. 1996. “3-D Optical data storage and engraving in transparent materials.” In Ultrafast Phenomena X, edited by W.H. Knox P.F. Barbara, J.G. Fujimoto and W. Zinth, Pp. 157–158. Springer Verlag. Publisher's VersionAbstract
    We present a novel method for 3-D optical data storage and internal engraving that has sub-micron resolution, provides a large contrast in index of refraction and is applicable to a wide range of transparent materials.
    E. N. Glezer. 1996. “Techniques of ultrafast spectroscopy.” In Spectroscopy and Dynamics of Collective Excitations in Solids, edited by B. Di Bartolo, Pp. 375–416. Plenum. Publisher's VersionAbstract
    This chapter begins with a general introduction to ultrafast spectroscopy, considers the limits of time and frequency resolution, and reviews the linear and nonlinear propagation of light pulses in a dispersive medium. Next, the basic elements of ultrashort laser pulse generation are described, including gain medium requirements, mode-locking mechanisms, compensation for group velocity dispersion, and pulse amplification. The last section deals with the measurement of ultrashort pulses, including joint time-frequency techniques, and also describes pulse-shaping in the frequency domain.
    R. J. Finlay, T. Her, S. Deliwala, C. Wu, W. D. Mieher, and E. Mazur. 1996. “Surface femtochemistry: What is the role of substrate electrons?” In FEMTOCHEMISTRY: Ultrafast Chemical and Physical Processes in Molecular Systems, edited by M. Chergui, Pp. 457–464. World Scientific. Publisher's VersionAbstract
    The desorption of O2 from O2/Pt(111) and the formation of CO2 from CO/O2/Pt(111) are measured following excitation at various laser wavelengths with pulse durations from 80-fs to 3.6-ps. The trends in the reaction yield reflect a reaction mechanism in which substrate electrons out of thermal equilibrium interact with the adsorbates. We also demonstrate a rudimentary control of branching ratio using subpicosecond ultraviolet laser pulses.
    E. Mazur. 1996. “Interaction of ultrashort laser pulses with solids.” In Spectroscopy and Dynamics of Collective Excitations in Solids, edited by B. Di Bartolo, Pp. 417–468. Plenum. Publisher's VersionAbstract
    Beginning with some basic considerations in electromagnetic theory and solid state physics, I hope, in these four lectures, to develop some appreciation for the wonderfully rich electronic and optical properties of solids and to present an overview of current research in the area of the interaction of ultrashort laser pulses with solids. The first two lectures are tutorials on the electronic and optical properties of solids and on energy transfer and relaxation in semiconductors. While some of the introductory material is treated in undergraduate courses, I will try to paint a broad picture and connect a number of facts that often remain disconnected. This introduction is followed by a survey of optical measurements of carrier and phonon dynamics in solids. I will conclude with an overview of recent experiments on electronic and structural changes induced by intense short laser pulses, including work done in my own research group.
    Y. Siegal, E. N. Glezer, L. Huang, and E. Mazur. 1994. “Laser-induced bandgap collapse in GaAs.” In . Ultrafast Phenomena in Semiconductors. Publisher's VersionAbstract
    We present recent time-resolved measurements of the linear dielectric constant of GaAs at 2.2 eV and 4.4 eV following femtosecond laser pulse excitation. In sharp contrast to predictions based on the widely-used Drude model, the data show an interband absorption peak coming into resonance first with the 4.4-eV probe photon energy and then with the 2.2-eV probe photon energy, indicating major changes in the band structure. The time scale for these changes ranges from within 100 fs to a few picoseconds, depending on the incident pump pulse fluence.
    J. Kai Wang, Y. Siegal, P. N. Saeta, N. Bloembergen, and E. Mazur. 1993. “Femtosecond, Electronically-Induced Disordering of GaAs.” In Ultrafast Phenomena VIII, edited by G. A. Mourou J.-L. Martin, A. Migus and A. H. Zewail, Pp. 420–421. Springer-Verlag. Publisher's VersionAbstract
    Excitation of GaAs with a femtosecond laser pulse leads to disordering in less than 100 femtoseconds, before appreciable lattice heating through phonon emission.
    K. Hsien Chen, C. Lu, E. Mazur, N. Bloembergen, and M. J. Shultz. 1989. “Multiplex CARS study of infrared-multiphoton-excited OCS.” In Laser Spectroscopy IX, edited by A. Mooradian M. Feld and J. Thomas, Pp. 232–233. Academic Press. Publisher's VersionAbstract
    {Coherent anti-Stokes Raman spectroscopy (CARS) is a sensitive and efficient technique to monitor molecular vibrational and rotational distributions. This paper reports on the application of CARS to study the dynamics of OCS after infrared multiphoton excitation. The OCS molecule has three widely separated fundamental modes ( V1 = 859 cm1
    K. Y. Christina Lee, D. S. Chung, S. Rno, and E. Mazur. 1989. “Fourier transform heterodyne spectroscopy of liquid interfaces.” In Laser Materials and Laser Spectroscopy, edited by Z. Wang and Z. Zhang, Pp. 316–319. World Scientific. Publisher's VersionAbstract
    By acousto-optically shifting the local oscillator in a heterodyne set-up, a spectral resolution of better than 150 mHz can be obtained. Applications of the technique to the study of interfacial phenomena are discussed.