Simultaneous trapping of high and low refractive index particles using a single-fiber optical trap with coexisting LP01 and LP11 modes.

We propose and demonstrate a fiber optical trap based on the coexistence of LP01 and LP11 modes for the simultaneous trapping of both high refractive index particles and low refractive index particles. Since different mode beams have different propagation constants, they exhibit different focused light fields. We fabricated a tapered fiber probe using thermal fusion to converge the beam, which generates a strong gradient force field near the fiber tip, as well as a dark trap along the axial direction. High refractive index particles are attracted near the fiber tip by a strong gradient force, and low refractive index particles are trapped in the dark cage along the axial direction. The proposed optical trap, which can simultaneously trap particles with different refractive indices, makes it easier to manipulate cells or molecules with different properties and explore multi-molecule interactions, which can facilitate research related to biology and chemistry.

Towards Cleaner Production Ecosystem: An Analysis of Embodied Industrial Pollution in International Trade of China's Processing versus Normal Exports.

While promoting economic growth, industrial development is causing serious environmental problems and threatening human health. Studies on pollution transfer through international trade often over-estimate the actual embodied emissions in exports and ignore the industrial pollutants. By designing a non-competitive input-output model which differentiates between processing exports and normal exports, we calculate the embodied domestic and imported industrial emissions in China's processing and normal exports and imports. We also calculate the balance of embodied emission in trade (BEET) and the pollution terms of trade (PTT), as well as the decomposition of scale, structural, and technical effects on embodied emission in international trade. The results demonstrate that processing exports reduce domestic pollution by importing intermediate inputs; normal exports, on the other hand, have a considerable impact on domestic pollution. Bilateral trade between China and the US has the most detrimental impact on China's local environment, followed by trade between China and Japan. China's exports to Japan are more polluting per unit than those to the US and Germany. Technological upgradations and transformation of trade structure have helped to reduce the negative environmental consequences of China-US and China-Japan bilateral trade. Investment in technology and trade policy can lead to a cleaner production ecosystem.

All-fiber rotation speed measurement based on dual-beam speckle interference.

An all-fiber rotation speed measurement structure based on dual-beam speckle interference is proposed. A distributed feedback laser as the light source generates two independent laser beams through a coupler and two circulators. Scattered by the object, the two laser beams interfere separately with the light reflected from the ends of the two fibers, which can be used to measure the rotation speed. The experiment results show that the structure can accurately measure the rotation speed of the object, with relative errors less than 0.5%.