Light receiving device, light receiving device manufacturing method, and light receiving method

1. A light receiving device comprising:

a polarization dispersing section that disperses a polarization direction of incoming light into a plurality of polarization directions;

a light collecting section that has a metal pattern shaped like concentric circles on a surface thereof, the light collecting section collecting light that has passed through the polarization dispersing section; and

a light receiving section that receives the light collected by the light collecting section.

2. The light receiving device as set forth in claim 1 , wherein

the light collecting section has a surface plasmon antenna that has the metal pattern shaped like the concentric circles on a surface thereof, and

the light receiving section receives the light collected toward a center of the concentric circles of the metal pattern of the light collecting section, through a hole at the center of the concentric circles, on a rear side of the light collecting section.

3. The light receiving device as set forth in claim 2 , wherein

the polarization dispersing section disperses a polarization direction of incoming linearly polarized light into a plurality of polarization directions that radiate from the hole formed in the light collecting section.

4. The light receiving device as set forth in claim 1 , wherein

the polarization dispersing section has a liquid crystal cell in which liquid crystal molecules are oriented in a single direction on a first surface and liquid crystal molecules are oriented in a radial or concentric manner on a second surface.

5. A manufacturing method for a light receiving device that receives incoming light, comprising:

forming a polarization dispersing section that disperses a polarization direction of the incoming light into a plurality of polarization directions;

forming a light collecting section that has a metal pattern shaped like concentric circles on a surface thereof, the light collecting section collecting light that has passed through the polarization dispersing section; and

forming a light receiving section that receives the light collected by the light collecting section.

6. The manufacturing method as set forth in claim 5 , wherein

forming the light collecting section includes forming the light collecting section having a surface plasmon antenna that has the metal pattern shaped like the concentric circles on a surface thereof, and

forming the light receiving section includes forming the light receiving section that receives the light collected toward a center of the concentric circles of the metal pattern of the light collecting section, through a hole at the center of the concentric circles, on a rear side of the light collecting section.

7. The manufacturing method as set forth in claim 5 , wherein

forming the polarization dispersing section includes forming the polarization dispersing section having a liquid crystal cell in which liquid crystal molecules are oriented in a single direction on a first surface and liquid crystal molecules are oriented in a radial or concentric manner on a second surface.

8. The manufacturing method as set forth in claim 7 , wherein

forming the polarization dispersing section includes:

treating a liquid-crystal-side surface of a liquid crystal orientation film at the first surface so as to orient the liquid crystal molecules in the single direction;

treating a liquid-crystal-side surface of a liquid crystal orientation film at the second surface so as to orient the liquid crystal molecules in the radial or concentric manner; and

enclosing liquid crystal between the liquid crystal orientation film at the first surface and the liquid crystal orientation film at the second surface.

9. The manufacturing method as set forth in claim 8 , wherein

forming the polarization dispersing section includes:

forming the second surface of the polarization dispersing section by applying the liquid crystal orientation film onto a surface of the light collecting section on which the metal pattern is formed as the concentric circles;

forming the liquid crystal orientation film of the first surface; and

enclosing the liquid crystal between the liquid crystal orientation film of the first surface and the liquid crystal orientation film of the second surface.

10. The manufacturing method as set forth in claim 7 , wherein

forming the polarization dispersing section includes:

applying a liquid crystal orientation film onto a transparent flat electrode and treating the liquid crystal orientation film so as to orient liquid crystal molecules in a single direction, to form the first surface of the polarization dispersing section;

applying a liquid crystal orientation film onto a transparent circular pattern electrode, to form the second surface of the polarization dispersing section;

enclosing liquid crystal between the first surface and the second surface;

raising a temperature of the liquid crystal to a phase transition temperature or higher;

lowering the temperature of the liquid crystal to reach a temperature lower than the phase transition temperature while radial electric fields are kept applied by the flat electrode and the circular pattern electrode.

11. A light receiving method comprising:

dispersing a polarization direction of incoming light into a plurality of polarization directions;

collecting the dispersed incoming light by using a light collecting section that has a metal pattern shaped like concentric circles on a surface thereof; and

receiving the collected light.