We propose an efficient scheme to control Goos–Hänchen (GH) shifts of the reflected and transmitted beams in a cavity containing Er3 + -doped yttrium-aluminum-garnet (YAG) crystal with a four-level Er3 +  ionic system. It is found that both the values and signs of the reflected and transmitted GH shifts can be coherently controlled by tuning the relevant optical parameters, such as the incoherent pumping rate, and the intensity and detuning of the driving field. Furthermore, we propose a scheme for such a configuration of the reflected GH shift as a family of reflection-type optical switchings. It is shown that the average port spacing and reflectivity of the optical switching can reach approximately 1.03 mm and 16.88, respectively, which indicate the high performance of switching function. Our proposal may provide a possibility to implement optically tuned optical switching.

No abstract

We present an optical method for the manipulation of microparticles using two tilted-focused beams. First, the action on the microparticles is studied with a single tilted-focused beam. The beam is used to drive the directional motion of a dielectric particle. When the optical scattering force is larger than the optical gradient force, the particle is pushed to the tilted side of the optical axis by the optical force. Second, two tilted-focused beams with the same power and complementary tilt angles are used to assemble an optical trap. The trap can be used to realize the optical trapping of the dielectric particles and opto-thermal trapping of the light absorbing particles. The trapping mechanism is the balance of the forces exerted on the particles, including the optical scattering force, optical gradient force, gravity, and thermal gradient force. The trap center is away from the focal spots, which effectively prevents the laser beam from being focused on the trapped object.

This paper mostly summarizes experimental device of laser-induced plasma and taking pictures of plasma plume. The progress in the experimental study on laser-induced plasma was discussed. The experimental apparatus include the laser、delay device; The system of the plasma radiation gathered and radiation received were reviewed. In addition, photos of plasma plume were discussed; at last, dynamic process of laser-induced plasma plume explosion was discussed.

In this paper,machine translation and computer-aided translation are researched, in conjunction with the problems that the author encountered with the existing translation tools when translating mechanical engineering files, the necessity and idea of the mechanical engineering translation computer-aided tool brought forward. This tool aims at mechanical engineering translation features, improves speed and quality of mechanical engineering translation, ignores the language complexity and ambiguity, and introduces a mechanism of symbols for words and expressions. According to this paper, the PTCAT is designed and implemented.