UC Irvine

Photoacoustic Microscopy (PAM) is a noninvasive imaging method with high acoustic resolution and high optical contrast. It can image deeper tissues than optical microscopy methods, such as multi-photon fluorescence microscopy and optical coherence tomography (OCT). Current scanning mechanism in photoacoustic microscopy is mainly based on positional stage, mirror galvanometer and microelectromechanical system (MEMS). My thesis proposes a novel scanning mechanism using Lead zirconate titanate (PZT), which is one type of piezoelectric ceramics. In my study, the PZT raster scanner is fabricated by mounting a multi-mode optical fiber onto the PZT, which is controlled by a functional generator. When a resonant frequency signal is applied to the PZT, the fiber tip will be vibrated, resulting in a raster scanning light beam in one-dimension. Two-dimensional scanning can be realized by combining another orthogonally mounted PZT. Compared with scanning systems such as the linear stage, mirror galvanometer and MEMS, the PZT scanning system has a faster scanning speed, while preserving satisfactory resolution and a sufficient field-of-view (FOV). In addition, the low cost and compatible configuration of the scanner make it promising for the PAM system to be used in clinical application.