Oct2007ChrisWorkPhotoCHRISTOPHER M. LAWSON, Professor, Department of Physics

Associate Executive Director, Alabama EPSCoR

Director, Center for Optical Sensors and Spectroscopies (COSS)

University of Alabama/Birmingham (UAB),
PHONE: (205) 975-5059, E-Mail: mailto:lawson@phy.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.  This work has led to the development of the first materials that can be used for power limiting in  the blue region, phosphine-substituted oligothiophenes.  Other applications include high speed communications, advanced laser radar, fiber-optic switching networks, photonic phase array antennas,

Administrative Duties / Links:

  • Director, UAB Center for Optical Sensors and Spectroscopies (COSS)  (click the link for more information on COSS)
    • The purpose of the Multi-Institutional “Center for Optical Sensors and Spectroscopies” is 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. 
  • Asssociate Executive Director, Alabama EPSCoR (click the link for more information on Alabama EPSCoR)

·         Alabama EPSCoR is a consortium of academic, government and industry organizations established in 1985.  Seven Ph.D. granting institutions constitute the EPSCoR program in Alabama include:  Alabama A&M University, Auburn University,   Tuskegee University, University of Alabama, University of Alabama at Birmingham, University of Alabama in Huntsville, and the University of South Alabama.  The primary goal of the consortium is to establish the infrastructure, capacity and capability needed to increase sustained national science and technology research competitiveness. 

·         Alabama’s investment in the ALEPSCoR program (averaging 470K/year since 2006) has led to $ 24M in new federal awards in calendar year 2008 being brought into the state.  These new awards include: 

·         A new NSF Research Infrastructure Improvement Cooperative Agreement was awarded in September 2008 for a total of $ 15 million for five years; 

·         A total of $6.5 M in new Co-funding awards ($3.2 M in direct NSF EPSCoR Co-funding, supplemented by $ 3.3 M in NSF Directive funding);

·         Two new DoE EPSCoR federal-state partnership awards for a total of $ 900K;

·         Six new NASA Seed Grant RID (Research Infrastructure Development) totaling $ 180K; and

·         Three new USDA EPSCoR projects totaling $1.5. Click the link for more information.

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:

  • Class Lecture Notes.
  • 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):

  • D. Myrex, G. Gray, A. VanEngen Spivey, C. Lawson, “Synthesis and Characterization of Transition Metal Systems Containing Phosphino-Oligothiophene Ligands for Nonlinear Optical Materials”, Organometallics 25, (2006) 5045-5050.
  • 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).