Patent ID: 8477297
Filing Date: 2013-07-02
Classification: B29D,G01M

Abstract:
1. A refractive index distribution measuring method of measuring a refractive index distribution of an object using a first medium having a first refractive index and a second medium having a second refractive index, the first and second refractive indices being different from each other and from a refractive index of the object, the method comprising: a transmitted wavefront measuring step of causing a reference light to enter the object placed in the first medium to measure a first transmitted wavefront of the object, and of causing the reference light to enter the object placed in the second medium to measure a second transmitted wavefront of the object; a reference transmitted wavefront calculating step of calculating a first reference transmitted wavefront of a reference object acquirable when causing the reference light to enter the reference object placed in the first medium, the reference object having a known shape and a known refractive index distribution, and of calculating a second reference transmitted wavefront of the reference object acquirable when causing the reference light to enter the reference object placed in the second medium; a refractive index distribution calculating step of calculating the refractive index distribution from which a shape component of the object is removed, using the first and second transmitted wavefronts and the first and second reference transmitted wavefronts, wherein the transmitted wavefront measuring step measures the first transmitted wavefronts by causing the reference light to enter the object placed in plural placement states in the first medium, and measures the second transmitted wavefronts by causing the reference light to enter the object placed in the plural placement states in the second medium; and an alignment error calculating step of calculating an aberration sensitivity with respect to changes of the placement state of the object, and of calculating an alignment error of the object in each of the plural placement states in the measurements of the first and second transmitted wavefronts, using the aberration sensitivity and the first and second transmitted wavefronts measured in the plural placement states, wherein the reference transmitted wavefront calculating step calculates the first and second reference transmitted wavefronts respectively acquirable when causing the reference light to enter the reference object placed in placement states including the alignment errors in the first medium and the second medium.