The study of laser cooling of TeH- anion in theoretical approach.

The probabilities of laser cooling of TeH- anion via a spin-forbidden transition and a three-electronic-level transition are proposed. The potential energy curves of the X1Σ+, a3∏, A1∏, and b3Σ+ electronic states of tellurium monohydride anion (TeH-) are calculated using multi-reference configuration interaction method. Davidson corrections, core-valence correlations and spin-orbit coupling effects are also considered. The AWCV5Z-PP pseudopotential basis set of Te atom is used. Spectroscopic parameters of the Λ-S and Ω states are obtained by solving radial Schrodinger equation. These results are reported at the first time. Permanent dipole moments of the Ω states and transition dipole moments of the a21↔X0+ and A1↔X0+ transitions are also calculated. Highly diagonally distributed Franck-Condon factors of the a21↔X0+ and A1↔X0+ transitions are obtained, the value of f00 is 0.9970 and 0.9980, respectively. Spontaneous radiative lifetimes of the a21 and A1 excited states are predicted. i.e. τ(a21) = 200.3 ns and τ(A1) = 84.3 ns. Only the main pump laser is required to driving a21↔X0+ and A1↔X0+ transitions. The laser wavelengths both are in the visible region. Doppler temperatures and recoil temperatures of laser cooling TeH- anion are also predicted.

Quantitative generation of microfluidic flow by using optically driven microspheres.

Microfluidic flow generation plays a fundamental role in microfluidic systems and shows potential for applications in basic biology and clinical medicine. In this study, an enabling technology is proposed to quantitatively generate microfluid flow through the automatic movement of a microsphere in liquid by using optical tweezers. A closed-loop control strategy with visual servoing feedback is introduced to achieve high precision and robustness. The theoretical solution of the generated microfluid is obtained on the basis of Stokes equations. An experimental method is proposed, and experiments are performed to verify the effectiveness of our approach. This method does not impose any dedicated fabrication of microtool, and the microfluidic flow can be dexterously adjusted by controlling the direction, speed, and distance of the microsphere from a target location. To the best of our knowledge, this is the first demonstration of optically actuating liquids through the translational movement of microspheres with closed-loop control. The proposed method will be useful in various biomedical applications needing quantitative, precise and controllable localized microfluid.