2018 BFY III Abstract Detail Page

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Abstract Title: W05: Quantum Harmonic Oscillator Fluorescence
Abstract: The quantum harmonic oscillator (QHO) is a problem examined with differing levels of mathematical rigor in modern physics and quantum mechanics courses. Although there are numerous gaseous molecules that can be modeled as a QHO, experiments investigating vibrational spectroscopy have not found wide use in BFY laboratory instruction because of various difficulties in implementation and maintenance.  We present a QHO experiment that is rock solid, inexpensive and easy to implement.

The QHO system studied is the molecule S2- which is the activator in over a dozen natural minerals found worldwide.  With a modicum of attention given to laser and cryogenic safety, students assemble the optical setup and collect fluorescence spectra from which they determine the energy level spacing and effective spring constant for the excited state QHO levels. With further analysis, deviations from the quadratic potential energy up to the x6 term can be determined.  Excitation from the ground to excited manifold of energy levels is accomplished by a violet diode laser or even a 405nm handheld laser pointer. At room temperature, the emission spectrum is very broad with some observable structure.  At liquid nitrogen temperatures, visible spectral lines evenly-spaced in wavelength can be detected in a matter of minutes with a USB spectrometer.
Abstract Type: Workshop

Author/Organizer Information

Primary Contact: Daniel Boye
Davidson College
Physics Department
Box 7133
Davisdon, NC 28035
Phone: 7048942394
Co-Author(s)
and Co-Presenter(s)
Mario Belloni and Larry Cain
Physics Department
Davidson College

(address same as above)

Workshop Documents

Workshop Doc 1: Download the Workshop Doc 1
Workshop Doc 2: Download the Workshop Doc 2
Workshop Doc 3: Download the Workshop Doc 3