Spectroscopy and laser cooling on the $^{1}S_{0}-\,^{3}P_{1}$ line in Yb via an injection-locked diode laser at 1111.6nm

Abstract

We generate 555.8nm light with sub-MHz linewidth through the use of laser injection-locking of a semiconductor diode at 1111.6nm, followed by frequency doubling in a resonant cavity. The integrity of the injection lock is investigated by studying an offset-beat signal between slave and master lasers, by performing spectroscopy on the $(6s)^{2}$ $^{1}S_{0}-\,(6s6p)$ $^{3}P_{1}$ transition in magneto-optically trapped ytterbium, and by demonstrating additional laser cooling of $^{171}$Yb with the 555.8nm light. For the $^{1}S_{0}-$ $^{3}P_{1}$ spectroscopy, we confirm the linear dependence between ground state linewidth and the intensity of an off-resonant laser, namely, that used to cool Yb atoms in a $^{1}S_{0}-$ $^{1}P_{1}$ magneto-optical trap. Our results demonstrate the suitability of injection locked 1100-1130nm laser diodes as a source for sub-MHz linewidth radiation in the yellow-green spectrum.