  Simulating real-time scenarios to predict optical trapping behavior for
continuous wave (CW) as well as femtosecond pulsed lasers is a challenging
problem. This is especially so, because, for a tightly focused laser, one must
also include optical Kerr effect as well as thermal nonlinearity. We show here
the distinct differences between CW and femtosecond pulsed laser mediated
optical trapping via their effect in scattering and gradient forces in the
Rayleigh regime. In our newly developed model, it will also be easier to
predict the stability of the trap in real optical trapping scenario as well as
provide information regarding choice of solvents, probes, and optical
parameters like laser type, power range, wavelength, etc. as may the cases be.
