雷射干涉術已經發展成一項重要的量測工具，從微小角度、微小位移、絕對距離、表面輪廓、到生化上的光學活性等，皆廣泛地使用雷射干涉技術。在各種的干涉術中，外差干涉術是一種極為重要且廣泛使用的技術。它具有快速反應、易與其它技術結合及量測精確度高的優點。在本論文中，我們將對外差干涉術的基本原理、電光晶體的移頻方式、全反射臨界角基本原理與外差干涉儀的基本架構做說明。最後，並使用外差干涉術量折射率時所產生誤差來源做討論與分析。 本文提出一個以共光程多次全反射外差干涉術，組成一個具有高解析度之折射率量測系統，可應用於如一般均勻液體濃度、藥劑性質、生物醫學…..等方面的量測，其折射率解析度可以到達 。 Interferomtry of laser has develop to be a important measurement application which is applied widely, such as small angle, small displacement, absolute distance, surface roughnessm,optical avtivity in biochemical domain etc. In kind of interferometers, heterodyne with the advantages of reacting quickly, combining with the other techniques easily, high sensitivity, is one of the important technique and also applied wide. In this paper, a method of measurement about Common Optical Path Multi Total Internal Reflect with Heterodyne Interferometry which compose a index measurement system of high sensitivity is announced. This system could be applied on measurement of common concentration of solution, medicine, biomedicine etc. It’s predicted the measured resolution of index could achieve the scale of .
