Optical device, method of manufacturing optical device, and method of manufacturing optical device chip

1. An optical device, comprising:

a fiber array that has input optical fibers and output optical fibers, wherein the input optical fibers and the output optical fibers are grouped into an array of fiber pairs, such that each of the input optical fibers is paired with a corresponding output optical fiber, from among the output optical fibers;

a lens array that has lenses, wherein each of the lenses collimates input light from a corresponding input optical fiber, from among the input optical fibers;

a photodiode array that has photodiodes, wherein each of the photodiodes receives the input light collimated by a corresponding lens, from among the lenses, and outputs an electrical signal according to a power of the received input light;

a light branching layer, disposed between the lens array and the photodiode array, that branches the input light, from each of the input optical fibers, into a first branched light propagating toward the corresponding output optical fiber and a second branched light propagating toward a corresponding photodiode from among the photodiodes;

a first spacer, disposed between the fiber array and the lens array, that transmits the input light from each of the input optical fibers to the corresponding lens;

a second spacer, disposed between the lens array and the light branching layer, that transmits the input light passing through each of the lenses to the corresponding photodiode; and

a third spacer, disposed between the light branching layer and the photodiode array, that transmits the input light passing through light branching layer to the corresponding photodiode, wherein

the fiber array, the first spacer, the lens array, the second spacer, the light branching layer, the third spacer, and the photodiode array are laminated in this order.

2. The optical device according to claim 1 , further comprising:

an aperture plate, having an aperture for each fiber pair, disposed between the third spacer and the photodiode array, wherein

the aperture:

suppresses returning light from the corresponding output optical fiber propagating to the corresponding photodiode, and

transmits the input light, from the corresponding input optical fiber, to the corresponding photodiode.

3. The optical device according to claim 1 , wherein the first spacer comprises:

a through hole, for each input optical fiber, that transmits the input light from the corresponding input optical fiber to the corresponding lens; and

an inner wall around the through hole that suppresses the input light from the corresponding input optical fiber propagating to another lens other than the corresponding lens.

4. The optical device according to claim 1 , wherein the second spacer comprises:

a through hole, for each lens, that transmits the input light permeating through the corresponding lens to the corresponding photodiode, and

an inner wall around the through hole that suppresses the input light permeating through the corresponding lens from propagating to another photodiode other than the corresponding photodiode.

5. The optical device according to claim 1 , wherein

channels are one-dimensionally or two-dimensionally arrayed in a direction orthogonal to a lamination direction, and

each of the channels comprises one of the input optical fibers aligned, in the lamination direction, with the corresponding lens and the corresponding photodiode.

6. A method of manufacturing an optical device, the method comprising:

preparing a plurality of components for lamination, including the fiber array, the first spacer, the lens array, the second spacer, and the photodiode array constituting the optical device according to claim 1 , wherein

at least a subset of the plurality of components for lamination are prepared with a mark for positioning, and

the plurality of components for lamination are laminated while positioning the mark as a reference.

7. A method of manufacturing an optical device chip, the method comprising:

preparing an optical device comprising:

a fiber array that has input optical fibers;

a lens array that has lenses, wherein each of the lenses collimates input light from a corresponding input optical fiber, from among the input optical fibers;

a photodiode array that has photodiodes, wherein each of the photodiodes receives the input light collimated by a corresponding lens, from among the lenses, and outputs an electrical signal according to a power of the received input light;

a first spacer, disposed between the fiber array and the lens array, that transmits the input light from each of the input optical fibers to the corresponding lens; and

a second spacer disposed between the lens array and the photodiode array, that transmits the input light passing through each of the lenses to a corresponding photodiode from among the photodiodes, wherein

the fiber array, the first spacer, the lens array, the second spacer, and the photodiode array are laminated,

channels are one-dimensionally or two-dimensionally arrayed in a direction orthogonal to a lamination direction, and

each of the channels comprises one of the input optical fibers aligned, in the lamination direction, with the corresponding lens and the corresponding photodiode; and

fragmenting, by cutting, the optical device in the lamination direction in order to manufacture an optical device chip having fewer channels than the optical device.

8. The method of manufacturing the optical device chip according to claim 7 , wherein the cutting is performed using a femtosecond laser.

9. A method of manufacturing an optical device chip, the method comprising:

preparing a plurality of components for lamination, including a fiber array, a first spacer, a lens array, a second spacer, and a photodiode array constituting an optical device comprising:

the fiber array that has input optical fibers;

the lens array that has lenses, wherein each of the lenses collimates input light from a corresponding input optical fiber, from among the input optical fibers;

the photodiode array that has photodiodes, wherein each of the photodiodes receives the input light collimated by a corresponding lens, from among the lenses, and outputs an electrical signal according to a power of the received input light;

the first spacer, disposed between the fiber array and the lens array, that transmits the input light from each of the input optical fibers to the corresponding lens; and

the second spacer disposed between the lens array and the photodiode array, that transmits the input light passing through each of the lenses to a corresponding photodiode from among the photodiodes, wherein

the fiber array, the first spacer, the lens array, the second spacer, and the photodiode array are laminated,

channels are one-dimensionally or two-dimensionally arrayed in a direction orthogonal to a lamination direction, and

each of the channels comprises one of the input optical fibers aligned, in the lamination direction, with the corresponding lens and the corresponding photodiode;

laminating the plurality of components for lamination; and

fragmenting, by cutting, the optical device in the lamination direction in order to manufacture an optical device chip that is a fragment of the optical device, wherein

the optical device chip has fewer channels than the optical device.