Nonlinear optical tweezers for longitudinal control of dielectric particles

A model of the optical tweezers using thin layer of organic dye as the addition nonlinear lens in configuration is proposed. The expressions of the focal length of nonlinear lens, intensity distribution of reshaped Gaussian beam, and total longitudinal optical force acting on dielectric particles are theoretically derived using paraxial approximation. The influence of the average power of incoming Gaussian laser beam, thickness of thin layer, and nonlinear coefficient of refractive index on properties of nonlinear optical tweezers are numerically observed. The results also are discussed to find out the conditions that the dielectric particle could be stable trapped and finely controlled by tuning of average power of incoming laser beam.