Detection of 532-nm frequency-doubled Nd:YAG radiation in an active rubidium atomic resonance filter.

We report the detection of frequéncy-doubled Q-switched Nd:YAG laser radiation at 532.24 nm by an active rubidium atomic resonance filter. The Rb 5p level was populated by using a diode laser operating at 795 nm. The 532-nm laser excited atoms to the 10s level; these decay through p levels to the ground state. Signals were observed at 420/422 nm and 359 nm, corresponding to fluorescence from states 6p and 7p. Fluorescence noise was observed only on the 420/422-nm transition; the 359-nm signal had no detectable noise.