LASER,OPTO MICROENGINE ROTATED BY QUANTAM EFFECTS

我们提出了一种光微引擎作为提供光能的微执行器。利用分子气体动力学效应，实现了光微发动机的旋转。由于转子表面的摩擦损失会在微观长度的尺寸量级上影响旋转扭矩，因此降低摩擦损失具有重要意义。然后，我们注意到将单光束梯度光学陷阱应用到光微引擎中。在本研究项目中，讨论了微米级介质球在光线光学作用下，单光束梯度辐射压力对激光陷阱作用力的计算。光辐射压力由入射光线角度和相对折射率来估算。结果表明，要想获得好的俘获效果，需要高数值孔径(N.A.)产生的高会聚光束。目标。利用捕获实验装置，实现了激光对纯水中直径为5微米的微细颗粒的捕获，揭示了气体相对分子质量对激光微引擎性能的影响。氦气、Ar和Zenon被用作运行光学微型发动机的环境气体。随着气体分子量的减小，发动机的最大静扭矩增大。采用直接模拟蒙特卡罗方法对光微发动机周围气体分子的运动进行了数值模拟。数值模拟结果表明，发动机叶片前后表面的压差与气体分子质量有关。

We propose a opto-microengine as a micro-actuator supplied optical energy. The opto-microengine is rotated by the molecular gas dynamics effects. As the friction loss on the surface of the rotor effects the torque of rotation at the size-order of microscopic length, it is important to decrease the friction loss. Then we notice to apply single-beam gradient optical trapping to the opto-microengine. In the present research project the calculation of the forces for laser trap by single-beam gradient radiation pressure on micron-sized dielectric spheres in the regime of the ray optics are discussed. The optical radiation pressure is evaluated by incident ray angle and a relative index of refraction. It is shown that good trapping requires high convergence beams produced by a high numerical aperture (N.A.) objective. By using the trapping experimental facilities it is realized that the fine particles with 5 micro-meter diameter in pure water are trapped by the laser beam.In this rsearch project the effects of gas molecular weights on laser opto microengine performance are revealed. Helium, argon, and zenon are used as an environmental gas for operating of the opto microengines. With decreasing the gas molecular weights, the maximum static torques of the engines increase. Gas molecular motions around the opto-microengines are numerically simulated by the Direct Simulation Monte Carlo method. The numerical results by the DSMC method show that the pressue differemces between forward and backward surfaces of the engine blades are dependent on the gas molecular weights