Measurement of the 87Rb[5P3/2(F'=3)-5S1/2(F=2)] Effective Nonradiative Relaxation Rate near a Metallic Film

We have studied the effective nonradiative relaxation rate of the hyperfine level 87Rb[5P3/2(F'=3)] near a metallic film with diode laser-induced retrofluorescence spectroscopy and saturated-absorption spectroscopy technique. The glass-vapor interface is considered as two distinct regions, a wavelength-thickness vapor layer joined to the surface and a more remote vapor region. The total experimental retrofluorescence signal Sob(vL) is the summation of the signal originating from the far-field region ST(vL) and the signal originating from the near-field region sn(vL). Considering the thermalization of 87Rb(5P3/2) atoms in the far-field region, we can approximate ST(vL) by using the vertical fluorescence signal near the entrance window. Thus we get the experimental hyperfine signal profile of 87Rb in the near-field region. The value of the effective nonradiative transfer rate AF'=3--<F=2nf=2.3 X 108s-1 near the metallic film is relatively large compared to the spontaneous emission rate AF'=3--<F=2=1.1X107s-1