| 摘要 |
<p>A light branching unit and a reflecting mirror are fixed to a barrel in a state where the distance between the members is constantly maintained. And, a laser beam from a light source is guided to the light branching unit via an optical fiber, separated to a measurement beam and a reference beam by a beam splitter, and a synthesized light of the measurement beam and the reference beam that reciprocate between the light branching unit and the reflecting mirror in the liquid is then guided to a photodetection system via the optical fiber. And, the measurement beam and the reference beam are made to interfere inside this photodetection system, and a change of an optical path length of the measurement beam is measured based on a photoelectric conversion signal of the interference light. Accordingly, change of a refractive index of the liquid can be optically measured.</p> |
