Abstract
Abstract In this thesis, we present a new method for angle measurement and further utilize the method to measure the thermal coefficient of the refractive index of fused silica. In the angle measurement, a collimated laser beam reflected from a mirror mounted on a rotatable plate is detected by a linear CCD array. The lateral displacement induced by the angular displacement of the mirror is then determined by computing the shift of the center of the detected beam profile. The beam's traveling distance between the rotatory mirror and the CCD array is set to be 1.3 meters in our experiment. To make the whole optical system compact, we use a pair of highly reflective mirrors to confine most of the optical beam path in between the pair of mirrors. Both analysis and the experimental results show that a resolution of 3.16 10 radians for angle measurement can be reached. In measuring the thermal coefficient of the refractive index of fused silica, we apply the same technique as for the angle measurement, in which a prism made of fused silica is used to deflect a laser beam. The lateral displacement caused by the thermally-induced change of the refractive index of the prism material is detected by a linear CCD array. Experimental results show that a refractive-index change of 10 can be detected by using the proposed method.