Diode Laser Spectroscopy
Buffalo State College, July 9–11, 2018
(One or two set-ups available)
Figure 1: Apparatus set up for simultaneously doing saturated absorption spectroscopy and using an unequal arm Michelson to calibrate the laser frequency sweep.
Figure 2: Left: Doppler broadened absorption lines. Right: SAS absorption lines within Doppler curve.
After looking at the laser modes, we will expand the wavelength range by linking the sweep of the laser current to the piezo sweep of the grating angle. Using mirrors and beam-splitters we will create overlapping, counter-propagating ‘pump’ and probe’ beams. This optical configuration produces saturated-absorption or ‘Doppler-free’ spectroscopy. Limited only by the natural linewidth (<10MHz, out of an optical frequency of about 385 million MHz) of the atomic transitions, we will look at absorption lines that would otherwise be unobservable in a gas near room temperatures. Once comfortable with the apparatus, participants will be able to choose several of the following projects, depending upon their particular interests or the topics they feel will be most relevant for their students.
After completing his Ph.D. at the University of Buffalo, where Jonathan Reichert was his thesis advisor, George Herold worked at TeachSpin for several months designing some of the electronics for its first pulsed NMR, PS1-A. A few postdoc positions later, he signed on as a staff scientist at the W. M. Keck Free Electron Laser at Vanderbilt University. The threat of funding loss combined with incipient fatherhood brought George back to Buffalo, where TeachSpin had grown enough to need another full-time physicist. His first jobs were to complete the development of the Optical Pumping apparatus and build, from first wires, the Signal Processor/Lock-In. At TeachSpin George continues to develop elegant instruments, do the final pre-shipment testing that provides reference data for many instruments, and generally trouble-shoot both construction and user questions.
George Herold, Ph.D., Senior Scientist, Teachspin, Inc., 2495 Main Street, Suite 409, Buffalo NY 14214-2153. Email: email@example.com.