Sensing apparatus

• US 8,989,573 B2
• Filed: 03/28/2013
• Issued: 03/24/2015
• Est. Priority Date: 04/05/2012
• Status: Active Grant

• Current Assignee: Gwangju Institute of Science and Technology
• Original Assignee: Gwangju Institute of Science and Technology
• Inventors: Park, Chang-soo, Kim, Young-bok, JEON, Sie-Wook
• Primary Examiner(s): Bello, Agustin
• Application Number:
  US13/852,759
• Publication Number:
  US 20130266321A1
• Time in Patent Office: 726 Days
• Field of Search: 398 25- 33, 398 83- 85, 398/214, 25022714-22719
• US Class Current: 398/33
• CPC Class Codes: H04J 14/005 Optical Code Multiplex
• CPC Class Codes: H04J 14/0223 Conversion to or from optical TDM

Abstract

A sensing apparatus includes: a broadband optical source; a first pseudorandom number generator generating a first pseudorandom number code string to modulate the broadband optical source; at least one sensor reflecting an output of the first pseudorandom number generator at a wavelength corresponding to a center wavelength thereof when the output of the first pseudorandom number generator is inputted; a wavelength-time converter converting an output of the sensor by wavelength-time conversion; a second pseudorandom number generator generating a second pseudorandom number code string which is different in frequency from and is the same in bit length and code string as the first pseudorandom number code string; a mixer mixing an output signal of the wavelength-time converter with an output signal of the second pseudorandom number generator; and an integrator integrating an output of the mixer.

Claims

1. A sensing apparatus comprising:

a broadband optical source;

a first pseudorandom number generator generating a first pseudorandom number code string to modulate the broadband optical source;

at least one sensor reflecting an output of the first pseudorandom number generator at a wavelength corresponding to a center wavelength thereof when the output of the first pseudorandom number generator is inputted;

a wavelength-time converter converting an output of the sensor by wavelength-time conversion;

a second pseudorandom number generator generating a second pseudorandom number code string which is different in frequency from and is the same in bit length and code string as the first pseudorandom number code string;

a mixer mixing an output signal of the wavelength-time converter with an output signal of the second pseudorandom number generator; and

an integrator integrating an output of the mixer.

2. The sensing apparatus according to claim 1, wherein the broadband optical source comprises a high luminance light emitting diode.

3. The sensing apparatus according to claim 1, wherein the broadband optical source comprises a semiconductor optical amplifier.

4. The sensing apparatus according to claim 1, wherein the broadband optical source comprises a reflective semiconductor optical amplifier.

5. The sensing apparatus according to claim 1, further comprising an optical amplifier amplifying the modified broadband optical source and inputting the modified and amplified broadband optical source to the sensor.

6. The sensing apparatus according to claim 1, wherein the sensor comprises a reflector reflecting a wavelength corresponding to a center wavelength thereof.

7. The sensing apparatus according to claim 6, wherein the reflector is connected to an output terminal of the broadband optical source.

8. The sensing apparatus according to claim 6, wherein the reflector is a Bragg grating or a thin dielectric filter having single wavelength full reflection or partial reflection characteristics.

9. The sensing apparatus according to claim 1, further comprising a light detector provided between the wavelength-time converter and the mixer.

10. The sensing apparatus according to claim 9, further comprising a band pass filter provided between the wavelength-time converter and the light detector and having a wavelength corresponding to a wavelength of each sensor.

11. The sensing apparatus according to claim 9, further comprising an electric signal amplifier provided between the light detector and the mixer to amplify an output of the light detector.

12. The sensing apparatus according to claim 1, wherein the at least one sensor comprises a plurality of sensors which are distributed in series, in parallel, in a ring shape, in a star shape, or in a bus shape.

13. The sensing apparatus according to claim 1, further comprising an interface device providing a user with a variation in time in an output of the integrator.

14. The sensing apparatus according to claim 13, wherein the interface device is an oscilloscope.

15. A sensing apparatus comprising:

a broadband optical source;

a first pseudorandom number generator generating a first pseudorandom number code string to modulate the broadband optical source;

a optical amplifier amplifying the modulated broadband optical source;

at least one sensor reflecting an output of the first pseudorandom number generator at a wavelength corresponding to a center wavelength thereof when the output of the first pseudorandom number generator is inputted;

a wavelength-time converter converting an output of the sensor by wavelength-time conversion;

a light detector converting an output of the wavelength-time converter to an electrical signal;

an electrical signal amplifier amplifying an output of the light detector;

a second pseudorandom number generator generating a second pseudorandom number code string which is different in frequency from and is the same in bit length and code string as the first pseudorandom number code string;

a mixer mixing an output signal of the electrical signal amplifier with an output of the second pseudorandom number generator; and

an integrator integrating an output of the mixer.

16. The sensing apparatus according to claim 15, wherein the broadband optical source comprises at least one of a high luminance light emitting diode, a semiconductor optical amplifier, or a reflective semiconductor optical amplifier.

17. The sensing apparatus according to claim 15, wherein the sensor comprises a reflector reflecting a wavelength corresponding to a center wavelength thereof.

18. The sensing apparatus according to claim 17, wherein the reflector is connected to an output terminal of the broadband optical source.

19. The sensing apparatus according to claim 17, wherein the reflector is a Bragg grating or a thin dielectric filter.

20. A sensing apparatus comprising:

a broadband optical source;

a first pseudorandom number generator generating a first pseudorandom number code string to modulate the broadband optical source;

at least one sensor reflecting an output of the first pseudorandom number generator at a wavelength corresponding to a center wavelength thereof when the output of the first pseudorandom number generator is inputted;

a second pseudorandom number generator generating a second pseudorandom number code string which is different in frequency from and is the same in bit length and code string as the first pseudorandom number code string;

a mixer mixing an output signal of the sensor with an output signal of the second pseudorandom number generator; and

an integrator integrating an output of the mixer.