本文主要利用角度放大器結合了表面電漿共振感測器與外差干涉術進行微小位移量測。微小位移促使面對面之兩平面鏡中的某一鏡面產生一個角度偏移,當光線進入二鏡面中多(N)次反射,其出射光角度變化正比於鏡面偏移角之N倍,因此此鏡面角度放大了N倍,在使此光束入射一SPR感測器,藉由SPR對角度偏向的靈敏度以及共光程外差干涉術,可輕易地將SPR感測器因角度變化所引起之相位變化取出角度來推算位移量之大小。未加入SPR感測器其最小移動量可達到0.13 μm,加入SPR感測器其最小移動量可達到0.08 μm,最大量測範圍可到1000 μm。
In this paper, a combination of an angular amplifier, a surface plasmon resonance(SPR) sensor and the common-path heterodyne interferometry is used to measure small displacements in real-time. Two mirror face to face and nearly parallel is used to be an angular amplifier. A beam is incident into the angular amplifier, the output beam is reflected N times which is decided by the incideut angle and the size of the mirror. When a displacement causing one mirror deflective and then angle causes the beam deflect N times of the deflective angle. We can use the common-path heterodyne interferometry to measure the phase shift of SPR to measure the angle deviation and the displacement. The range of displacement measurement can be extended to 1000 μm and the resolution can reach to 0.08 μm.