SPECTROSCOPY ON A MODULATED MAGNETOOPTICAL TRAP

We demonstrate a new type of high-resolution two-photon frequency modu lation (FM) spectroscopy with cold atoms in a magneto-optical trap. In stead of modulating the probe as in ordinary FM spectroscopy, we modul ate the trap itself by FM of the trapping beams. We present theoretica l as well as experimental results for both absorption and polarization rotation spectroscopy. Finally, we demonstrate two-photon FM spectros copy, using the intrinsic phase noise of the trapping diode lasers. (C ) 1998 Optical Society of America.