CHRISTOPHER M. LAWSON, Professor, Department of Physics
Director, Center for Optical Sensors and Spectroscopies (COSS)
University of Alabama/Birmingham (UAB),
(205) 975-5059, E-Mail: lawson@uab.edu, WEB: http://www.phy.uab.edu/~lawson/

Nonlinear Optics and Optical Sensing/Imaging

My long term research interests are directed toward the development and characterization of nonlinear optical (NLO) materials for optical switching and power limiting applications using wavelength tunable Z-scan, degenerate four wave mixing (DFWM), and power limiting spectroscopy.  The focus of this work is to study the relationship between excited state absorption, linear absorption, and molecular structure in metal organics using computer modeling supported by a full suite of experimental measurements. 

I am also the Director of the Multi-Institutional “Center for Optical Sensors and Spectroscopies” to develop laser and fiber optic spectroscopic sensors for detection of explosives and chemical and biological toxins.  These sensors for toxins could have important environmental monitoring applications to help improve the safety and quality of local ground water supplies.  More importantly, when incorporated in airport screening systems, such optical sensors for explosives and chemical and biological toxins could have important Counter-Terrorism applications to help prevent import of explosives and dangerous chemical and biological agents. 

Administrative Duties / Links:

Instrumentation:

  • Pulsed nanosecond and picosecond Nd:YAGt, Ti:Sapphire, color center, and alexandrite lasers for nonlinear optics experiments.
  • Pulsed nanosecond and picosecond Optical Parametric Oscillator for broadband wavelength tunable laser pulses
  • Argon and Ti:Sapphire Lasers for Optical Imaging Experiments
  • A large assortment of fiber optics equipment for fiber optic sensor development.

Teaching:

  • Regularly teaches several undergraduate College Physics classes and an Applications of Optics graduate/undergraduate course sequence. The first course of this sequence covers paraxial optics, matrix theory, and computer optical design (using CODE-V). The second course covers interferometry, coherence, diffraction, and lasers. The third course covers nonlinear optics and optical interactions in materials.

Recent Books (1996-present):

  • T. Yeates, K. Belfield, F. Kajzar, and C. Lawson (Co-Editors), Nonlinear Optical Transmission and Multiphoton Processes in Organics, published by International Society for Optical Engineering, Bellingham, Washington, SPIE Vol. 5211, 148 pages (2003).
  • Coherence Gated Holograms, D. Brown and C. Lawson, in Holography for the New Millennium, H.J. Caulfield, J.E. Ludman, and J.R. Riccobono eds., Springer-Verlag New York, Inc., New York, NY, pp. 101-119 (2002), ISBN 0-387-95334-5.
  • Multiphoton Absorption and Nonlinear Transmission Processes: Materials, Theory, and Applications, K. Belfield, S. Caracci, F. Kajzar, C. Lawson, and A. Yeates (Co-Editors), SPIE Vol. 4797, 320 pages (2002).
  • Nonlinear Optical Transmission Processes and Organic Photorefractive Materials, C. Lawson and K. Meerholz (Co-Editors), published by the International Society for Optical Engineering, Bellingham, Washington, SPIE Vol. 4462, 228 pages (2001).
  • Linear, Nonlinear, and Power Limiting Organics, CM. Eich, M. Kuzyk, and C. Lawson, (Co-Editors), International Society for Optical Engineering (SPIE), Bellingham, Washington, SPIE Vol. 4106, 418 pages (2000).
  • Power Limiting Materials and Devices, C.M. Lawson (Editor), published by International Society for Optical Engineering (SPIE), Bellingham, Washington, SPIE Vol. 3798, 178 pages (1999).
  • Nonlinear Optical Liquids for Power Limiting and Imaging, C.M. Lawson (Editor), published by International Society for Optical Engineering (SPIE), Bellingham, Washington, SPIE Vol. 3472, 180 pages (1998).
  • Structure-Property Relationships In Transition Metal-Organic Third-Order Nonlinear Optical Materials, G. Gray and C. Lawson, pp. 1-27, Chapter I of Opto-Electronic Properties of Inorganic Compounds, edited by M. Roundhill & J. Fackler (Plenum Publishing Co., N.Y., N.Y., 1998).
  • Nonlinear Optical Liquids and Power Limiters, C.M. Lawson (Editor), published by International Society for Optical Engineering (SPIE), Bellingham, Washington, SPIE Vol. 3146, 188 pages (1997).
  • Nonlinear Optical Liquids, C.M. Lawson (Editor), published by International Society for Optical Engineering (SPIE), Bellingham, Washington, SPIE Vol. 2853, 210 pages (1996).

Selected Journal Articles (1998-Present):

  • M. McKerns, W. Sun, C. Lawson, and G. Gray, “Higher-Order Triplet-Triplet Interaction in Energy-Level Modeling of Excited-State Absorption for an Expanded Porphyrin Cadmium Complex”, Journal of the Optical Society of America B, Vol. 22, pp. 852-861 (2005).
  • VanEngen Spivey, V. Fedorov, M. McKerns, C. Lawson, and S. Mirov, “Amplification of narrow line LiF:F2+** color center laser oscillation, Optics Communications, Vol. 254, pp. 290-298 (2005).
  • M. Floyd, G. Gray, A. VanEngen Spivey, C. Lawson,  T. Pritchett, M. Ferry, R. Hoffman, and A. Mott, “Synthesis, X-ray Crystal Structures and Linear and Nonlinear Optical Characterization of a Series of Nickel(II) and Copper(II) Salicylaldiminato Complexes”, Inorganica Chimica Acta, Vol. 358, pp. 3773-3785 (2005). 
  • C. Byeon, M. McKerns, W. Sun, T. Nordlund, C. Lawson, and G. Gray, “Excited State Lifetime and Intersystem Crossing Rate of Asymmetric Pentaazadentate Porphyrin-Like Metal Complexes”, Applied Physics Letters Vol. 84, pp. 5174-5176 (2004).
  • Degenerate Four-Wave Mixing and Z-Scan Measurements of Stilbazolium Derivatives, W. Sun, C. Lawson, G. Gray, C. Zhan, D. Wang, Applied Physics Letters Vol. 78, pp. 1817-1819 (2001).
  • Third-Order Nonlinear Optical Properties of an Expanded Porphyrin Cadmium Complex, W. Sun, C. Byeon, C. Lawson, G. Gray, D. Wang, Applied Physics Letters Vol. 77, pp. 1759-1761 (2000).
  • Third Order Nonlinearity and Optical Limiting of Dichloromethane Solutions of cis-Mo(CO)4(PPh3)2, W. Sun, C. Lawson, and G. Gray, Optics Communications Vol. 180, pp. 361-366 (2000).
  • Third Order Susceptibilities of Asymmetric Pentaazadentate Porphyrin-Like Metal Complexes, W. Sun, C. Byeon, C. Lawson, G. Gray, D. Wang, Applied Physics Letters 74, pp. 3254-3256 (1999).
  • Coherence-Based Imaging Through Turbid Media via DFWM In Thin Liquid Crystal Films and Photorefractives, D. Brown, V. Fleurov, P. Carroll, and C. Lawson, Applied Optics Vol. 37, pp. 5306-5312 (1998).
  • Optical Limiting Performances of Asymmetric Pentaazadentate Porphyrin-Like Cadmium Complexes, W. Sun, C.C. Byeon, M.M. Mckerns, C.M. Lawson, G.M. Gray, and D. Wang, Applied Physics Letters Vol. 73, pp. 1167-1169 (1998).
  • Oxidative Enhancement of the third order susceptibility of solutions of cis-Mo(CO)4L2 (L=PPh3, AsPh3, PPh2Np) complexes as measured by DFWM, W. Sun, C.C. Byeon, M.M. Mckerns, C.M. Lawson, J.M. Dunn, M. Hariharasarma, G.M. Gray, Optical Materials Vol. 11, pp. 87-94 (1998).

Conference Organization:

    • Organized and Chaired “Media Perspectives” Session and Panel at the NSF EPSCoR National Meeting in Las Vegas, Nevada, 2003 (See under “Agenda” at http://www.nevada.edu/epscor/natlconference.html)
    • Organized and Chaired 2003 Annual EPSCoR Meeting at The Capital Auditorium, State Capital, Montgomery, Alabama March 13, 2003, including Special Legislative Breakfast for Alabama State Legislators and University Presidents
    • Co-Organized Multiphoton Absorption and Nonlinear Transmission Processes: Materials, Theory, and Applications II, Annual SPIE Meeting in San Diego, California August, 2004

 

At National EPSCoR Meeting with Alabama State Senator Steve French