Endoscope OCT Optical Fiber Scanning Probe Design Based On PZT And Driving Method To Achieve

Optical coherence tomography (OCT) is a new optical imaging technology developed in the 90's. The optical coherence tomography system based on miniaturized optical fiber scanning probe can integrate with an endoscope, catheter or needle, which allows for high-resolution in vivo imaging with millimeters penetration depth. Therefore, it has important significance to develop a small-sized fast scanning probe for OCT technology.An endoscope 2D fiber scanning probe based on PZT is designed for optical coherence tomography (OCT) imaging. The fiber in the 2D scanning probe is driven by two piezoelectric ceramic and a thin conductive substrate.A finite element model on the electromechanical coupling of the piezoelectric scanning probe is established. By using the finite element analysis software ANSYS11.0, the model analysis on the PZT scanning probe is carried out and the deformation of the model is obtained. The effects of different size and voltage on vibration mode are also analyzed.In consideration with resonance characteristics of the optical fiber probe cantilever, two orthogonal vibrations of the fiber cantilever can be excited by imposing mixing signals with frequency close to optical fiber's resonant frequency on the piezoelectric ceramic, which accomplishes two-dimensional scanning of the fiber cantilever. The resonance characteristics are used to achieve line scanning in the driving method, which can improve the scanning range. In addition, nonresonant program is employed for filed scanning, which ensure that there is not blind spot during scanning. At last, a fiber probe is fabricated and the scanning images are obtained by using the fiber probe.