波向量編碼微小化雙光子螢光顯微鏡

Abstract

非線性顯微術，是一具三維高解析度的虛擬切片技術，並被廣泛運用在生物、化學以及醫學的研究上。近年來，因為醫療及工業上的需求，發展小型、可攜式、光纖化的非線性顯微鏡是一重要的研究課題。當前存在的微小光纖化非線性顯微鏡研究可分為兩大類，包括遠測掃描式(Distal Scanning)以及近側掃描(Proximal Scanning)機制兩種。目前所需探討的問題為如何有效利用光纖傳遞飛秒雷射和收集樣品的非線性訊號，及如何封裝微小型的的內視鏡探頭，而現存的遠側和近側兩類掃描機制尚且無法完全解決上述根本問題。在本論文中，我們首先提出了一種新穎的波向量編碼雷射掃描內視鏡。此內視鏡是藉由方型光纖傳遞光的波向量函數(其中雷射脈衝經由1公尺的光纖僅展寬1.28倍寬度)，並利用LabVIEW程式進行影像索引編碼，最後以1030 nm 飛秒雷射和螢光小球做為光源及樣品端來展示出雙光子螢光內視鏡。

Nonlinear laser scanning microscopy is a powerful virtual-biopsy tool for performing 3D structural and functional imaging of biological tissues. In recent years, to develop fiber-optic endo-microscopy is an important issue. Current fiber-optic nonlinear laser scanning endo-microscopy can be divided into two categories. One is proximal scanning mechanism by fiber-optic bundles and the other is distal scanning mechanism by packing a miniaturized scanner such as MEMS mirrors and PZT actuators, into the end of the nonlinear endoscope. However, there are three entanglement technical challenges include single-mode beam delivery of femtosecond excitation pulses, efficient collection of nonlinear signals from specimens, and a high-quality beam scanning mechanism within an ultra-compact package. There three challenges cannot be solved with both categories. In this work, we developed a novel design of nonlinear fiber-optic endoscope, a wave-vector-encoded nonlinear laser scanning endo-microscopy. In the endoscope, the wave-vectors of the scanned beams were delivered by a rectangular-shape fiber. Moreover, the pulse broadening ratio in a 1 meter long rectangular-shape fiber was as small as 1.28, which means the two-photon excitation efficiencies can be recovered by the fiber. By the position sensitive detection and a home-made LabVIEW programs, the wave-vectors after the fiber is recovered. Then by the recovered wave-vectors, the two-photon fluorescence microscopy images of fluorescence beads were performed to demonstrate the concept of wave- vector-encoded endoscope.