Laser trapping of 100nm diameter polystyrene bead under high repetition rate ultrafast pulsed excitation is studied
theoretically as well as experimentally. In our theoretical analysis, we explore the role of optical Kerr effect at
50mW average power under pulsed excitation. In our experiment, we use a CMOS camera to record two-photon
fluorescence signal from the trapped particle which decays with time due to photo-bleaching.