Linear and nonlinear time-dependent backscattering calculations for dielectric spheres are presented. The time-dependent backscattered linear fields depend upon: (1) the linewidth of the pulse and the linewidth of the resonance of the sphere, and (2) the frequency separation between the center frequency of the pulse and the resonance frequency of the sphere. When the refractive index or absorption of the sphere is intensity- dependent, then the backscattering also depends upon the intensity of the laser pulse. When the droplets have a large intensity-dependent index of refraction or a large saturable absorption, and are illuminated near a resonance with a high- intensity laser pulse, hysteresis may be seen in the back- scattered intensity.
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