中文摘要：

利用液晶空间光调制器对高斯光束进行相位调制后可生成涡旋光束。因涡旋光束本身具有轨道角动量,酵母细胞被光阱捕获后会绕其中心旋转,对酵母细胞旋转的时序信号图进行傅里叶变换后可测出酵母细胞在光阱中的旋转角速度。详细讨论了酵母细胞旋转角速度随激光功率、拓扑荷以及捕获高度的变化关系。实验结果表明,酵母细胞的旋转角速度与激光功率成正比,与拓扑荷的平方成反比;捕获高度在14μm时角速度达到最大值;细胞在涡旋光阱中的旋转方向可由拓扑荷的符号决定,正号为逆时针旋转,负号为顺时针旋转。此实验结果有望应用在细菌鞭毛马达力矩的测量实验中。

英文摘要：

Vortex optical trap is generated by projecting computer-generated phase patterns to liquid crystal spatial light modulator.Because vortex beam itself owns orbital angular momentum,it can be utilized to trap and rotate yeast cell.The angular rotation rate of yeast cell is measured by Fourier transforming of rotation time-sequencial signal.Besides,how laser power,topological charge and height of the vortex trap from bottom affect the angular rate of rotation is discussed in detail.The experimental results indicate that the rotation rate is proportional to laser power,but inversely proportional to the square of the topological charge.The rotation rate reaches maximum when the height of trap is about 14 μm.The sign of topological charge determines the direction of rotation of yeast cell.When the sign of topological charge is positive,the yeast cell rotates counter-clockwise,and it rotates clockwise when the sign is negative.The results may find their potential applications in the measurement of the torque of bacterial flagella motor.