Propagation of rotating elliptical Gaussian beams from right-handed material to left-handed material

By applying the ABCD matrix method, we report the propagating properties of the rotating elliptical Gaussian beams（REGBs） from the right-handed material（RHM） to the left-handed material（LHM）. Based on the propagation equation, we obtain the intensity distributions of the REGBs during the propagation. It is found that the rotating direction of the REGBs is opposite in the RHM and the LHM, and the rotation angles tend to be π /2 as the propagation distance is long enough.Then we analyze the relationship between the refractive index and the rotating velocity. Furthermore, the energy flow and the angular momentum（AM） of the REGBs which can rotate are also obtained.

Z-scan analysis of high-order nonlinear refraction effect induced by using elliptic Gaussian beam

The irradiance of an elliptic Gaussian beam that is high enough to excite high-order nonlinear refraction effect is used to calculate the normalized on-axis transmittance function in the z-scan technique by introducing complex beam parameters which make the calculation simpler. The transmittance formula is applied to the first-, first two-, and first three-order nonlinearities. Numerical evaluation shows that the symmetry no longer holds when using an elliptic Gaussian beam instead of a circular Gaussian beam. A distortion is observed in the central part of the curve, which decreases as ellipticity increases. Moreover, the variation of the normalized peak-valley difference decreases as ellipticity decreases.

Elliptic Gaussian Optical Beam in Nonlinear Conical Graded-index Rod Lens

The propagation and transformation of an elliptic Gaussian optical beam(EGB) passing through a Kerr-law nonlinear conical graded-index rod lens are presented.In the rod lens, the EGB is treated as two dependent optical beams.The dimensionless beam-width parameters and the inverses of the curvature radii for the wavefront of the two beams are given semi-analytically,and the transformations of the EGB with the rod lens are derived by use of the ABCD law of Gaussian optical beam.

Miniature optical force levitation system

Optical levitation technology is a new levitation technology for trapping micro/nano-particles.By taking advantage of the mechanical effect of light,it has the characteristics of non-contact and high sensitivity.However,the traditional optical levitation system is large in volume,complex in adjustment,and greatly affected by the external environment.Herein,a miniature optical levitation system based on a laser diode,miniature lenses,and a micro-electro-mechanical system(MEMS) particles cavity is proposed.First,we analyze the output spot characteristics of the laser diode.Being compared the characteristics of different kinds of laser diodes,the type,wavelength,and power of diodes in the levitation system are determined.Then,the micro-particles cavity is fabricated based on the MEMS process.The MEMS process is widely used in the manufacturing of micro-electronic devices because of its advantages of small size,high precision,and easy mass production.The particle cavity processed in this way can not only ensure the advantage of small volume,but also possesses high processing repeatability.The volume of the entire package including the light source,focusing lenses,and MEMS cavity is just Φ10 mm×33 mm,which is the smallest optical levitation system reported,to the best of our knowledge.After the entire levitation system is designed and set up,one silica particle of 10 μm diameter is stably trapped in the atmospheric environment.Finally,the micro-displacement and vibration signal are detected by a four-quadrant photoelectric detector to evaluate the stiffness of the optical levitation system.