Study of out-of-plane rotations in optical tweezers with usage in cellular biological systems

A rigid body can have 6 degrees of freedom, namely the three translational degrees of freedom and further, the three rotational degrees of freedom. Of these, the translational degrees have been well explored in optical tweezers community. However, only the in-plane rotational degree of freedom which we call the yaw motion in the nomenclature of the airlines, has been explored. The pitch and roll degrees are only beginning to be explored recently. In this talk, I will exhibit 4 ways of generating pitch rotation using the optical tweezers. I will also show you one way of detection of pitch rotation at high resolution using birefringent particles. Further, I will also discuss some applications of this pitch rotation in soft matter systems and biology, particularly usage to detect cell membrane fluctuations and rheology in the cell interior.