Optical arithmetic device and production method for optical arithmetic device

1 . An optical computing device comprising:

a light-diffraction element group comprising planar light-diffraction elements made of a photo-curable resin; and

a tubular body that houses the light-diffraction element group and that has an inner surface to which at least a part of a perimeter of each of the planar light-diffraction elements is fixed, wherein

a columnar body made of the photo-curable resin connects a first planar light-diffraction element of the light-diffraction element group to a second planar light diffraction element of the light-diffraction element group that is adjacent to the first planar light-diffraction element.

2 . An optical computing device comprising:

a light-diffraction element group comprising planar light-diffraction elements made of a photo-curable resin;

a tubular body that houses the light-diffraction element group and that has an inner surface to which at least a part of a perimeter of each of the planar light-diffraction elements is fixed; and

a light conversion layer that converts infrared light into visible light downstream of a last planar light-diffraction element of the planar light-diffraction elements.

3 . The optical computing device according to claim 2 , further comprising a diffusion layer that diffuses the infrared light to the visible light downstream of the last planar light- diffraction element.

4 . The optical computing device according to claim 3 , further comprising a spacer that defines a distance from the last planar light-diffraction element to the diffusion layer.

5 . A method for producing an optical computing device comprising: a light-diffraction element group comprising planar light-diffraction elements made of a photo-curable resin;

and a tubular body that houses the light-diffraction element group and that has an inner surface to which at least a part of a perimeter of each of the planar light-diffraction elements is fixed, the method comprising

molding integrally the light-diffraction element group inside the tubular body, wherein

a columnar body made of the photo-curable resin connects a first planar light-diffraction element of the light-diffraction element group to a second planar light diffraction element of the light-diffraction element group that is adjacent to the first planar light-diffraction element, and

the molding comprises forming the light-diffraction element group inside the tubular body in a sequential molding manner by:

either one of:

immersing a lower end of the tubular body in a photo-curable resin in an uncured state, or

injecting an uncured resin into the tubular body whose lower end is sealed; and

applying light from below for irradiation while the light-diffraction element group is lifted such that a part thereof is above the photo-curable resin upon completion of curing of the part.

6 . The method according to claim 5 , wherein

the tubular body transmits light for curing the photo-curable resin, and

the method further comprises fixing at least a part of a perimeter of each of the planar light-diffraction elements to an inner surface of the tubular body by applying light sideways through the tubular body for irradiation after the molding.

7 . The method according to claim 5 , wherein

the planar light-diffraction elements each comprise a through-hole,

the method further comprises discharging a photo-curable resin remaining between two planar light-diffraction elements that are adjacent by one or both of developing treatment and cleaning treatment after the molding,

in the developing treatment, a developer is injected into the tubular body, and

in the cleaning treatment, a cleaning liquid is injected into the tubular body.

8 . The optical computing device according to claim 1 , wherein the tubular body is filled with a liquid or a solid.

9 . The optical computing device according to claim 8 , wherein the liquid or the solid has a refractive index greater than 1 and smaller than a refractive index of the planar light-diffraction elements.

10 . The optical computing device according to claim 1 , wherein the tubular body has a greater Young's modulus than the light-diffraction element group has.

11 . The optical computing device according to claim 1 , wherein the tubular body has a smaller coefficient of thermal expansion than the planar light-diffraction elements have.

12 . The optical computing device according to claim 1 , wherein the tubular body transmits light for curing the photo-curable resin.

13 . The optical computing device according to claim 1 , wherein

the planar light-diffraction elements are each discoid, and

the tubular body is cylindrical.

14 . The optical computing device according to claim 1 , wherein the light-diffraction element group comprises one planar light-diffraction element comprising microcells each having an individually-set refractive index.