The Design And Analysis Of Optical Scanners For Optical Coherence Tomography

A miniature fiber optic scanner capable of two-dimensional scanning for medical imaging is designed and developed. The scanner is actuated externally using an electromagnet. Nickel gel, a soft ferromagnetic material, is coated on the optical fiber. The performance of the scanner is characterized. Finite element analysis is performed to validate the theoretical and experimental results. A design and analysis of a cantilever type electrostatic zipping actuator and a bidirectional vertical thermal actuator are presented. The actuation principle, lumped modeling analysis, experimental results, and finite element analysis of both actuators are presented. The actuators are characterized statically and dynamically using the optical profiler. The design consideration in displacement, electrostatic force, and electrostatic stability of the zipper actuator is presented. The zipper actuator is designed to withstand higher voltage and a mechanical structure is implemented to avoid the electrical shortage of the device. The thermal actuator is optimized to obtain higher displacement required for the MEMS scanner. The scanners using these actuators can be designed to be mounted on the 3D OCT probe which can be used for ex vivo imaging.