表面電漿共振(surface plasmon resonance, SPR)感測器可量測在固體與氣體或固體與液體界面之奈米膜層厚度與介電常數之微量變化。有別於一般單點或區域性之量測，利用表面電漿共振相位影像系統(phase image system)不僅可以提供大量平行空間資訊，且可獲得高靈敏之相位資訊。表面電漿共振相位偵測是利用同時包含有P-wave與S-wave之入射光激發表面電漿子(surface plasmons, SPs)，由於在SPR角時只有P-wave會因待測物條件改變而造成相位劇烈變化，S-wave則否，因此以量測反射光P-wave與S-wave之間相位差變化來獲得感測界面上之變化資訊。 本論文首先利用一改良式Mach-Zehnder移相干涉術(phase-shift interferometry, PSI)來觀測空間平面上之相位資訊，配合五步相位還原演算法來完成相位的重建。在此量測奈米膜層之相位影像差異並且討論此干涉方式之長時間相位穩定與空間解析度。為了獲得較佳的相位穩定度，論文中提出兩種共光程(common-path)之表面電漿共振相位干涉術，一為共光程外差式干涉術(heterodyne interferometry)，一為共光程液晶(liquid crystal)移相干涉術。利用共光程外差式干涉術結合鎖相放大(lock-in amplifier)技術解相位，具有光學機構簡單、高穩定度與動態量測之優點；而創新之共光程液晶移相干涉術不但具有上述之優點外還具有高解析影像資訊與價格低廉之優點，於長時間下之相位穩定可達10-3π並可靈敏的量測出5x10-6RIU之折射率變化。 Surface plasmon resonance (SPR) sensor can measure the thickness or dielectric constant change of nanolayer between solid-gas or solid-liquid interface. SPR phase image system not only can obtain high sensitivity phase information but also can provide high-throughout space information. Using the incident wave which including P-wave and S-wave to excite surface plasmon, P-wave has a violent phase jump and shift by the sample change in the resonance angle, and S-wave not. According to above, measure the phase difference of reflection wave between P-wave and S-wave to obtain SPR phase information. First, by use the modified Mach-Zehnder phase shifting interferometry and collocate five step phase reconstruct to measure the spatial phase variation of the nanolayer and discuss the phase stability and drift phenomenon. In order to obtain the long-term phase stability, the paper bring up two common-path SPR interferometry, the one is common-path heterodyne interferometry and the other is common-path liquid phase-shift interferometry. Common-path heterodyne interferometry that combine lock-in amplifier has several merits such as simple optical setup, high stability, high accuracy and rapid measurement. Common-path liquid phase-shift interferometry not only have several merits like above but provide high resolution and low cost. The phase stability can achieve 10-3π in long-term measurement and the sensitivity can achieve 5x10-6RIU.
