Abstract
Water has been proved to have anomalous physical properties in extended-nano space (10-1000 nm): high viscosity, low dielectric constant [1] and high proton mobility [2]. The information of structure is necessary to understand these phenomena systematically. Then, we chose the refractive index as the parameter related with the structure in extended-nano space. This parameter is also important when we perform measurement which requires it such as thermal lens microscopy in extended-nano space. We developed the method of measuring refractive index with alternating gratings, and measured refractive in extended-nano space and micro space. © 2009 CBMS.