Abstract

For atomic systems under strong influence of electromagnetic fields, the values of Einstein A and B coefficients have been observed to change from those of isolated atoms. However in our previous experiments which demonstrated the changes of A-coefficients, the self absorption of spontaneous emission was very strong and might the experimental result. In order to reduce the absorption drastically so that its effect can be neglected, we conducted a new experiment. In our new experiment, we measured the spontaneous emission from a very short discharge tube where the absorption was less than 4%. We also use a multichannel detector to monitor a number of spontaneous emission lines simultaneously. We observed that, as the incident photon flux increased, the intensity ratio of two spontaneous emission lines from the same upper level decreased. Any possible instrumental effect has been checked and eliminated. Therefore we can conclude that such observed decrement can only due to the change of Einstein A-coefficients.

© 1993 Optical Society of America