Patent ID: 11867624
Assignee: EVIDENT CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 5:
6. A refractive index distribution estimating system comprising:
an illumination optical system configured to illuminate a sample with partial coherent illumination;
an imaging optical system configured to form an optical image of the sample;
an image sensor configured to acquire a captured image from the optical image of the sample formed by the imaging optical system; and
a processor configured to reconstruct a refractive index distribution of the sample from the captured image, wherein the processor performs processing including the steps of:
estimating an estimation sample including a refractive index distribution of the sample;
calculating an image of the estimation sample by calculating a first intensity distribution at an imaging position of the imaging optical system corresponding to each of a plurality of light sources, using a first wavefront corresponding to each of the plurality of light sources that model an intensity distribution of a pupil of the illumination optical system, and summing the first intensity distribution corresponding to each of the plurality of light sources;
optimizing a refractive index distribution of the estimation sample using a second wavefront after the first wavefront corresponding to each of the light sources passes through the estimation sample, the captured image, and the image of the estimation sample;
updating the estimation sample by repeating calculation of the image of the estimation sample and optimization of the refractive index distribution of the estimation sample; and
reconstructing and outputting a structure of the estimation sample using a refractive index distribution of an updated estimation sample,

wherein, in the step of calculating the image of the estimation sample, the processor is configured to:
calculate the first wavefront corresponding to each of the plurality of light sources;
calculate the second wavefront after passing through the estimation sample corresponding to each of the first wavefronts;
calculate a third wavefront at a focus position on the sample side of the imaging optical system corresponding to each of the second wavefronts;
calculate a fourth wavefront at the imaging position of the imaging optical system corresponding to the third wavefront, using the third wavefront and a pupil function of the imaging optical system, and calculate a first intensity distribution corresponding to the fourth wavefront by squaring the fourth wavefront; and
calculate the estimation sample image by summing the first intensity distribution corresponding to the fourth wavefront.