Collimated blue light generation in rubidium vapor
Marcus Kienlen, Noah T. Holte, Hunter A. Dassonville +4 more
We describe an experiment for generating and characterizing a beam of collimated blue light (CBL) in a rubidium vapor. Two low-power, grating-feedback diode lasers, operating at 780.2 nm (5S1/2→5P3/2) and 776.0 nm (5P3/2→5D5/2), respectively, provide step-wise excitation to the 5D excited state in rubidium. Under the right experimental conditions, cascade decay through the 6P excited state will yield a collimated blue (420-nm) beam of light with high temporal and spatial coherence. We investigate the production of a blue beam under a variety of experimental conditions and characterize the spatial coherence and spectral characteristics. This experiment provides advanced undergraduate students with a unique opportunity to investigate nonlinear optical phenomena in the laboratory and uses equipment that is commonly available in laboratories equipped to investigate diode-laser-based absorption spectroscopy in rubidium.
American Journal of Physics•May 20, 2013•23 citations