Dr. Cristian Bahrim

Dr. Cristian Bahrim

Dr. Cristian Bahrim in the physics lab at Lamar University.

General Information

Education

  • Ph.D. University of Paris (Orsay), 1997
  • M.Sc. University of Bucharest
  • B.Sc. University of Bucharest

Links

Research Interests

  • Theoretical Atomic and Molecular Physics
    • Atomic collisions and interactions.  In collaboration with the experimental group of Professor Masahiro Hasuo from Kyoto University, Japan, we developed a theoretical model for explaining the depolarization mechanism in rare gas atoms induced by atomic collisions (see Refs. [1,3,6]).
    • Electron scattering on atoms (ions) with the formation of negative ions.  In the framework of a relativistic Dirac R-matrix model we investigated the electron-atom interaction, including correlation between electrons, with formation of negative ions (see Ref. [8]).
    • Theoretical molecular spectroscopy of transient molecules.  We investigated the formation of excimers using rare gas atoms.  This class of molecules can be used as active media in laser physics.  Our prototype system is the HeNe* molecule.  The excitation of the modes of vibration within bonding electronic potential wells, as predicted in Ref. [7], could trap the HeNe* molecules on quasi-bound states with a longer lifetime.
  • Interaction between light and matter in Classical and Quantum Optics
    • Electromagnetically induced transparency (EIT) in opaque systems.  The purpose is slowing down light in a bulk of atoms by inducing transparency as a result of coherent population trapping (CPT) due to quantum interference.  We developed a novel four-level atom W-system that could use two circularly polarized laser beams for performing binary recording of the optical information using a quantum optical coupling with a linearly-polarized laser beam (see Ref. [2]).
    • Polarization of light reflected by dielectric surfaces.  Optical characterization of dielectrics using the polarization of light incident at the Brewster angle.  We are able to measure the curve of dispersion of dielectrics by simply analyzing the reflection of light at surface.  This project has potential applications in forensic science (see Refs. [4,5]).
    • Atomic spectroscopy.  Using Grotrian diagrams and spectroscopic charts we analyze the atomic emission spectrum, and identify impurities.  We look for applications in the optical characterization of light sources, including measurements of the stars' surface temperature and their chemical composition.
  • Electron Diffraction by Crystals

Areas of Teaching

  • University/College Physics
  • Modern Physics
  • Optics/Photonics

Research with students on special projects (examples)

  • Undergraduate research
    • Sara-jeanne Vogler and Keeley Townley-Smith (2013) “Spectroscopy and polarimetry with applications in astronomy” (2013 Sigma Pi Sigma Award)
    • Nick Lanning, (2011) "Electron diffraction; Quantum optics" (McNair)
    • Richard Wooten (2006), "Light-matter interaction" (McNair)
    • Joseph Hunt (2005), "Atomic collisions and interactions" (McNair)
    • Joseph Young (2004), "Atomic Spectroscopy" (Goldwater)
  • Graduate research
    • Don Duplan, "Improved Brewster Angle Experiment using a Capacitor Induced Electric Field and Applications" (Master of Engineering Science in Electrical Engineering – June 2013).
    • Md Mozammal Raju “Optical Coupling between Two Lasers on a Dielectric Surface: Experimental and Theoretical Analysis” (Master of Engineering Science in Electrical Engineering – July 2014).

Selected Publications

[1] Matsukama, H., Tanaka, H., Takaie, Y., Shikama, T., Bahrim, C., and Hasuo, M. "Pertuber Dependence of Disalignment Cross Sections of the Argon 2p2 Atoms Measured at Temperatures between 77 and 295 K", Journal of Physical Society of Japan 81, art #114302 (2012).

[2] Bahrim, C., and Nelson, C. "Simultaneous electro-magnetically induced transparency for two circularly polarized lasers couled to the same lineraly polarized laser in a four-level atomic system in the W scheme", Physical Review A 83, art #033804 (2011).

[3] Bahrim, C, and Khadilkar, V, “Alignment relaxation of Ne*(2pi[J=1]) atoms induced by collisions with He(1s2) atoms in discharges at temperatures from 10 to 3000K”, Physical Review A 79, art#042715 (2009).

[4] Hsu, W-T, and Bahrim, C, “Accurate measurements of refractive indices for dielectrics in an undergraduate optics laboratory for science and engineering students”, European Journal of Physics 30, 1325-1336 (2009).

[5] Bahrim, C, and Hsu, W-T, "Precise measurements of the refractive indices for dielectrics using an improved Brewster angle method", American Journal of Physics, 77, 337-343 (2009).

[6] Bahrim C, and Khadilkar V, "Depolarization effects of the Ne*(2p2) atoms induced by isotropic collisions with He(1s2) atoms at temperatures between 10 and 1,000 Kelvin”, Journal of Physics B 41, art#035203 (2008).

[7] Bahrim C, and Hunt J F, “Infrared spectroscopy for the identification of modes of vibration in a temporary HeNe molecule”, Journal of Physics  B 39, 4683-4700 (2006).

[8] Bahrim C, Fabrikant I I, and Thumm U, “Boundary Conditions for the Pauli Equation: Application to Photodetachment of Cs-.“, Physical Review Letters 87, art#123003 (2001); 88, art# 109904 (2002).

Books/chapters

Co-editor to "Practical Applications of Educational Research and Basic Statistics" (2007), published by National Forum Journals, Houston, Texas, ISBN 0-9770013-4-2 and 2nd ed. by University Readers (2009).

Bahrim, C, “A modern optics laboratory for undergraduate students”, Chapter 17, 207-215, (2006) in the book Innovations 2006 - World Innovations in Engineering Education and Research, ed. by iNEER and Begell House Publishing (2006).