Richard I. Joseph

Professor of Electrical and Computer Engineering.

Education

        B.S.    1957    The City College of the City University of New York
        Ph.D.   1962    Harvard University

Research

In the near future, use of very short (femtosecond) pulses in optical fiber communication systems may lead to ultrahigh transmission rates and thus to a full exploitation of the enormous bandwidth of light. In a linear system, one of the fundamental drawbacks in achieving this goal is fiber dispersion which becomes of great significance in the femtosecond domain as a result of the inherent broad bandwidth. One way to overcome this is to carefully tune a highly monochromatic laser source at the wavelength for which the group dispersion is zero. In reality it is practically impossible to do this. Optical solitary waves provide an attractive solution to the above problem since the effects of dispersion can be balanced by the dependence of the index of refraction on intensity (nonlinearities). Higher-order solutions can also be used in pulse compression techniques and laser technology. For short enough time scales, there exists a satisfactory model for characterizing pulse propagation, the nonlinear Schroedinger equation. However, for femtosecond pulses the theory is considerably more complicated. Professor Joseph's research is concerned with the development of the theory to understand the propagation of such very short pulses.

In addition to the research described above, Professor Joseph's research interests also involve various aspects of solid state physics, electromagnetic wave propagation in various environmental and biological situations, and the application of the methods of statistical mechanics to an understanding of the ocean.

Selected Publications

R.I. Joseph and D.N. Christodoulides. ``Exact Field Decomposition for TM Waves in Nonlinear Media.'' Optics Letters, 12 (1987):826.

D.N. Christodoulides and R.I. Joseph. ``Vector Solitons in Birefringent Nonlinear Dispersive Media.'' Optics Letters, 13 (1988):53.

D.N. Christodoulides and R.I. Joseph. ``Discrete Self--Focusing in Nonlinear Arrays of Coupled Waveguides.'' Optics Letters, 13 (1988):794.

L.W. Hart, H.W. Ko, J.H. Meyer, D.P. Vosholz and R.I. Joseph. ``A Noninvasive Electromagnetic Conductivity Sensor for Biomedical Applications.'' IEEE Trans. Biomedical Engineering, 35 (1988):1011.

M.E. Thomas, W.J. Tropf and R.I. Joseph. ``Infrared Transmission of Sapphire, Spinel, Yttua and ALON as a Function of Temperature and Frequency.'' Optics Letters, 17 (1988):239.

D.N. Christodoulides and R.I. Joseph. ``Slow Bragg Solitons in Nonlinear Periodic Structures.'' Physical Review Letters, 62 (1989):1746.

K.R. Allen and R.I. Joseph. ``A Canonical Statistical Theory of Oceanic Internal Waves.'' J. Fluid Mechanics, 203 (1989):185.

K.R. Allen and R.I. Joseph. ``Relation between Lagrangian and Eulerian Spectra Based Upon a Canonical Statistical Theory of Geophysical Fluid Waves.'' Physical Review A, 39 (1989):5243.

D.N. Christodoulides and R.I. Joseph. ``Theory of Simulated Raman Scattering in Optical Fibers in the Pulse Walk-Off Regime.'' IEEE J. Quantum Electronics, 25 (1989):273.