入射光椭圆度对晶体微粒旋转角速度的影响

Effect of ellipse degree of incidence light on rotational angular velocity of the crystal particle

光致旋转技术在微机械和微生物等领域的应用越来越广泛。利用光束自旋角动量可以导致晶体微粒光致旋转的机理,从理论上分析了入射光椭圆度对晶体微粒旋转角速度的影响。通过MATLAB对不同激光功率下,光束的椭圆度与晶体微粒旋转角速度的关系进行数值模拟。结果表明:在实际对晶体微粒光致旋转操作中,晶体微粒能否旋转起来取决于光束椭圆度与微粒厚度之间的关系;在同一激光功率下,光束椭圆度与晶体微粒旋转角速度呈正旋曲线变化。因此,通过调节光束的椭圆度和较高的激光功率可以提高晶体微粒的旋转角速度。该结论对光驱动微机械马达的优化设计有一定的指导意义。

With the development of the optical technology, the application of optical rotation became more and more wide in MEMS and microorganisms field. In the paper the principle of optical rotation due to the transfer of spin angular momentum from light to particles was discussed by analyzing the interaction between the beam of light and birefringent crystal particles, and the effect of ellipse degree of incident light on the optical rotation was also analyzed theoretically. With MATLAB software, the variational relation between ellipse degree of incident light and rotation angular velocity was simulated under the different laser powers, and the result shows that the rotation of crystal particle depends on the relationship between ellipse degree and the thickness of particle in the actual operation. Under the same laser power, the simulated curve of ellipse degree and rotation angular velocity was sinusoidal, as a result, the rotation angular velocity of the crystal particle could be increased by adjusting the ellipse degree of incident light and the laser power in the experiment. The conclusion could be used to the choice of crystal particles and the optimization control of rotation frequency in actual application.