  We have experimentally studied the multiple side-band generation for
two-frequency components injected into a tapered amplifier and demonstrated its
effects on atomic laser cooling. A heterodyne frequency-beat measurement and a
Fabry Perot interferometer have been applied to analyze the side-band
generation with different experimental parameters, such as frequency
difference, injection laser power and tapered amplifier current. In laser
cooling potassium40 and potassium41 with hyperfine splitting of 1.3GHz and
254MHz, respectively, the side-band generation with a small frequency
difference has a significant effect on the number of trapped atoms.
