Abstract
To obtain the internal structure of a micron-sized microsphere, we propose the proximal two-beam optical tweezers as the precise microsphere rotational method. In this method, we harness the light pressure generated by light absorption as rotating torque. We decided to illuminate the proximal two points in each from different directions using two beams. In this case, the light pressure generated by light absorption is made to act as rotating torque. Using this proposed method, we can control the rotational velocity of a microsphere regardless of refractive index distribution by non-contact operation. In this paper, we mention the experimental results of rotating a microsphere whose diameter is 10μm by proximal two-beam optical tweezers. We obtain the projection images by rotating microsphere, and we convert the projection images into 3-dimensional absorption distribution by using filtered back projection which is known as a reconstruction method for computed tomography. To improve the adverse influences of refraction, we consider the illumination optics. As a result, the distribution of the internal submicron-defect in the microsphere can be analyzed.
