US 12,326,401 B2
Refractive index distribution standard
Michal Ziemczonok, Warsaw (PL); Arkadiusz Kus, Warsaw (PL); and Małgorzata Kujawinska, Lomianki (PL)
Assigned to POLITECHNIKA WARSZAWSKA, Warsaw (PL)
Appl. No. 17/595,574
Filed by POLITECHNIKA WARSZAWSKA, Warsaw (PL)
PCT Filed May 20, 2020, PCT No. PCT/IB2020/054772
§ 371(c)(1), (2) Date Nov. 19, 2021,
PCT Pub. No. WO2020/234791, PCT Pub. Date Nov. 26, 2020.
Claims priority of application No. 429994 (PL), filed on May 21, 2019.
Prior Publication US 2022/0228979 A1, Jul. 21, 2022
Int. Cl. G01N 21/41 (2006.01)
CPC G01N 21/41 (2013.01) [G01N 2201/13 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A refractive index distribution standard in the form of a three-dimensional object comprising in its volume a base medium and regions of variable size and distance with a refractive index different than that of the base medium, wherein the difference between the refractive index of said regions and the refractive index of the base medium is not greater than 0.04,
wherein said regions include at least: three first regions, a second region, and a third region,
wherein each of the first regions includes a set of at least two cuboids of variable size and distance, arranged parallel to each other and having a dimension in at least one direction similar to the resolving power of the measurement system under assessment, wherein said sets are oriented along respective perpendicular axes (X,Y,Z) for separate resolution assessment in each respective direction (X,Y,Z),
the second region is used for representing a cell nucleus and is ellipsoid-like or sphere-like in shape,
the third region has the shape of a cuboid or cylinder, and has gradient-based, slowly varying refractive index values, with a maximum refractive index variation range of 0.02,
wherein the base medium and the regions of the standard are made by means of two-photon polymerization process which uses a light beam to cure a photoreactive material in the form of a liquid substance in a highly localized and precise manner, and wherein the value of the refractive index at any point of the standard depends on the degree of polymerization of the photoreactive material and corresponds to a respective point of a predetermined three-dimensional numerical model of the standard.