1. A radiation detector comprising:
a radiation detecting unit including a radiation sensor detecting a radiation sensitive to light, a signal amplifier, a pulse-height discriminator, and a counter;
an optical pulse emitting unit configured to emit an optical pulse for confirming operational integrity of the radiation detecting unit;
an emission controlling unit configured to control an operation of the optical pulse emitting unit; and
a light path through which light is led from the optical pulse emitting unit to a vicinity of the radiation sensor,
the emission controlling unit including a mechanism for adjusting emission time characteristics of the optical pulse emitting unit.
2. The radiation detector according to claim 1, wherein the emission controlling unit includes a clock generator, a rising edge detector, a triangular wave generator, an amplifier, and a pulse-height discriminator, and the amplifier includes an amplification varying unit configured to adjust the emission time characteristics.
3. The radiation detector according to claim 2, wherein the amplification varying unit is composed of a variable resistor.
4. The radiation detector according to claim 1, wherein the emission controlling unit includes a clock generator, a rising edge detector, a triangular wave generator, an amplifier, and a pulse-height discriminator, and the pulse-height discriminator includes a discriminated pulse-height value varying unit configured to adjust the emission time characteristics.
5. The radiation detector according to claim 4, wherein the discriminated pulse-height value varying unit in the pulse-height discriminator is composed of a variable resistor.
6. The radiation detector according to claim 1, further comprising an amount-of-light adjusting mechanism adjusting an amount of light incident on the radiation sensor.
7. The radiation detector according to claim 6, wherein the amount-of-light adjusting mechanism has a configuration varying a distance from the end of the light path toward the radiation sensor to the radiation sensor, the incident light being led from the optical pulse emitting unit to a vicinity of the radiation sensor through the light path.
8. The radiation detector according to claim 1, further comprising a circuit board to which the radiation sensor is attached, and a filter provided around the circuit board and configured to adjust response characteristics of the radiation.
9. The radiation detector according to claim 8, wherein the filter along the light path has a thickness smaller than that of a remaining portion of the filter.
10. The radiation detector according to claim 8, wherein the filter is formed with a groove along which the light path is provided.
11. The radiation detector according to claim 8, wherein a portion of the filter along the light path is formed of a material different from a material of the remaining portion of the filter.
12. The radiation detector according to claim 1, wherein the light path has, at a tip end thereof, an extension made of a material similar to that of the light path.
13. The radiation detector according to claim 1, wherein the light path is formed of an optical fiber.
14. The radiation detector according to claim 1, further comprising a light sensor disposed at a portion near the radiation sensor for monitoring emission characteristics.
15. The radiation detector according to claim 14, wherein the emission time characteristics of the optical pulse emitting unit are adjusted in accordance with an output from the light sensor.
16. The radiation detector according to claim 14, wherein the distance from the end of the light path to the radiation sensor is varied in accordance with an output from the light sensor.
17. The radiation detector according to claim 14, wherein an amplification of the amplifier or a discriminated pulse-height value of the pulse-height discriminator is varied in accordance with an output from the light sensor.
18. The radiation detector according to claim 1, wherein the radiation sensor is composed of a silicon diode, a scintillator and a photomultiplier, or a semiconductor made of cadmium telluride.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What we claim is:
1. An apparatus for performing optical routing, comprising:
a metal layer having first and second sides;
a regular array of structures positioned along the first side;
an input optical waveguide positioned to illuminate a portion of the first side, the portion being adjacent to ones of the structures; and
a plurality of output optical waveguides positioned to receive light radiated from portions of the metal layer not illuminated by the input optical waveguide.
2. The apparatus of claim 1, wherein the first and second ones of the output optical waveguides are positioned to receive light radiated from different portions of the metal layer, the different portions having different angular positions about a point located in the regular array.
3. The apparatus of claim 1, further comprising another regular array of structures along the first side, the another regular array being positioned to cause surface plasmons to radiate light towards one of the output optical waveguides.
4. Then apparatus of claim 1, wherein the regular array comprises a plurality of rows of the structures, adjacent ones of the rows being separated by substantially the same distance.
5. The apparatus of claim 1, wherein each row comprises a series of the structures, adjacent structures of one of the series being separated by the same distance.
6. The apparatus of claim 1, further comprising:
a substantially transparent dielectric layer in contact with the first side of the metal layer.
7. The apparatus of claim 6, wherein the structures are selected from one of substantially identical holes in the metal layer and substantially identical holes in the dielectric layer.
8. The apparatus of claim 6, further comprising a device capable of varying the dielectric constant of the dielectric layer.
9. The apparatus of claim 1, further comprising a device capable of varying one of an incidence angle on the metal layer or a polarization for light emitted from the input optical waveguide.
10. A method, comprising:
producing a jet of surface plasmons on a metal surface in response to receiving an optical signal from an input optical waveguide;
selectively producing an optical signal in a first output optical waveguide from the produced jet in response to the received optical signal having a first wavelength; and
selectively producing an optical signal in a second output waveguide from the produced jet in response to the received optical signal having a second wavelength.
11. The method of claim 10, wherein the surface plasmons propagate in a first direction in response to the received optical signal having the first wavelength and the surface plasmons propagate in a second direction in response to the received optical signal having the second wavelength.
12. The method of claim 1O, further comprising producing a second jet of surface plasmons in response to the received optical signal having the first wavelength.
13. The method of claim 10, wherein the producing a jet includes illuminating a portion of a regular array of deformations along the metal surface with light from the optical signal.
14. An optical router, comprising:
a substantially transparent dielectric layer;
a metal layer with a first side that forms an interface with the dielectric layer;
an input optical waveguide positioned to illuminate a portion of the interface;
an output optical waveguide; and
wherein the interface is configured to cause light from the input waveguide to produce surface plasmons that radiate light to the output optical waveguide.
15. The apparatus of claim 14, further comprising:
a second output optical waveguide positioned to receive light via other surface plasmons; and
wherein the interface is configured to cause light from the input waveguide to produce the other surface plasmons.
16. The apparatus of claim 14, further comprising a regular array of deformations along the interface, the array configured to cause light from the input optical waveguide of a selected frequency to produce the surface plasmons.
17. The apparatus of claim 14, wherein the regular array comprises a plurality of rows of deformations, adjacent ones of the rows being separated by substantially the same distance.
18. The apparatus of claim 14, further comprising another regular array of deformations along the interface, the another array being configured to cause the surface plasmons to radiate light to the output optical waveguide.
19. The apparatus of claim 14, wherein the deformations are selected from one of holes in the metal layer and holes in the dielectric layer.