Optical signal processing apparatus and method

• US 6,661,935 B2
• Filed: 06/29/2001
• Issued: 12/09/2003
• Est. Priority Date: 03/11/1998
• Status: Expired due to Fees

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Tsutsumi, Makoto
• Primary Examiner(s): Robinson, Mark A.
• Assistant Examiner(s): Amari, Alessandro V.
• Application Number:
  US09/897,835
• Publication Number:
  US 20020031290A1
• Time in Patent Office: 893 Days
• Field of Search: 385/6, 359/280-284, 359/321, 359/324
• US Class Current: 385/6
• CPC Class Codes: G02F 1/0142 TE-TM mode conversion
• CPC Class Codes: G02F 1/09 based on magneto-optical elements, e.g. exhibiting Faraday effect
• CPC Class Codes: G02F 1/095 in an optical waveguide structure
• CPC Class Codes: G02F 1/2255 controlled by a high-frequency electromagnetic component in an electric waveguide structure
• CPC Class Codes: G02F 1/2955 by controlled diffraction or phased-array beam steering controlled diffraction for optical waveguide switching G02F1/313
• CPC Class Codes: G02F 2203/055 wavelength filtering
• CPC Class Codes: G02F 2203/24 beam steering

Abstract

An optical signal processing apparatus includes a YIG monocrystal serving as a magnetic body. A microstrip is provided on one main face of the YIG monocrystal, and microwaves are input to the microstrip. In order to input a laser beam into the YIG monocrystal, a semiconductor laser, a first lens, and a polarizer are disposed on the outside of one side surface of the YIG monocrystal with respect to the widthwise direction thereof. In order to detect a laser signal output from the YIG monocrystal, a analyzer, a second lens, and a photo detector are disposed on the outside of the other side surface of the YIG monocrystal with respect to the widthwise direction thereof.

Claims

1. An optical signal processing apparatus in which a microwave signal is applied to a strip line formed transversely to a general propagation direction on a magnetic body, in order to process an optical signal propagating through said magnetic body in said general propagation direction;

wherein a magnetic field is applied to said magnetic body; and

wherein said general propagation direction of the optical signal within said magnetic body, the propagation direction of the microwave signal, and the application direction of the magnetic field are substantially perpendicular to one another.

2. An optical signal processing apparatus according to claim 1, wherein said magnetic body is formed of a ferrite.

3. An optical signal processing apparatus according to claim 2, wherein said ferrite is an iron garnet.

4. An optical signal processing apparatus according to claim 3, wherein said iron garnet is YIG (yttrium iron garnet).

5. An optical signal processing apparatus according to claim 1, wherein said magnetic body is formed of a bulk monocrystal.

6. A TM-TE mode converter using the optical signal processing apparatus according to claim 1.

7. A filter comprising the optical signal processing apparatus according to claim 1 and a photo detector.

8. A filter according to claim 7, wherein said photodetector is movable with said magnetic body.

9. A filter according to claim 7, wherein said photo detector is selected from the group consisting of a photodiode, a phototransistor, a photoelectric tube, and a photo multiplier.

10. An optical signal processing apparatus according to claim 1, wherein said magnetic body is formed of a monocrystalline thin film.

11. An optical beam scanner using the optical signal processing apparatus according to claim 1.

12. An electromagnetic field sensor using the optical signal processing apparatus according to claim 1.

13. An optical signal processing apparatus according to claim 1, wherein the application direction of the magnetic field is substantially perpendicular to said strip line.

14. An optical signal processing method in which a microwave signal is applied to a strip line formed transversely to a general propagation direction on a magnetic body in order to process an optical signal propagating through the magnetic body in said general propagation direction;

wherein a magnetic field is applied to said magnetic body; and

wherein said general propagation direction of the optical signal within said magnetic body, the propagation direction of the microwave signal, and the application direction of the magnetic field are substantially perpendicular to one another.

15. An optical signal processing method according to claim 14, wherein said magnetic body is formed of a ferrite.

16. An optical signal processing method according to claim 15, wherein said ferrite is an iron garnet.

17. An optical signal processing method according to claim 16, wherein said iron garnet is YIG (yttrium iron garnet).

18. An optical signal processing method according to claim 14, wherein the application direction of the magnetic field is substantially perpendicular to said strip line.

19. An optical signal processing apparatus in which a microwave signal is applied to a strip line formed on a magnetic body, in order to process an optical signal propagating through said magnetic body;

and in which a photodetector receives said optical signal;

wherein said photo detector is selected from the group consisting of a phototransistor a photoelectric tube, and a photo multiplier;

wherein a magnetic field is applied to said magnetic body; and

wherein the strip line is formed transversely to a general propagation direction of the optical signal and said general propagation direction of the optical signal within said magnetic body, the propagation direction of the microwave signal, and the application direction of the magnetic field are substantially perpendicular to one another.

20. An optical signal processing apparatus according to claim 19, wherein said photodetector is movable with respect to said magnetic body.

21. An optical signal processing apparatus according to claim 19, wherein the application direction of the magnetic field is substantially perpendicular to said strip line.

22. An optical signal processing apparatus in which a microwave signal is applied to a resonant strip line formed on a magnetic body in order to process an optical signal propagating through said magnetic body;

wherein a magnetic field is applied to said magnetic body; and

wherein the strip line is formed transversely to a general propagation direction of the optical signal and said general propagation direction of the optical signal within said magnetic body, the propagation direction of the microwave signal, and the application direction of the magnetic field are substantially perpendicular to one another.

23. An optical signal processing apparatus according to claim 22, wherein said resonant strip line has a length related to a wavelength of said microwave signal.

24. An optical signal processing apparatus according to claim 23, wherein said length is half of the wavelength of said microwave signal.

25. An optical signal processing apparatus according to claim 23, wherein said length is defined by a pair of air gaps formed in said strip line.

26. An optical signal processing apparatus according to claim 25, wherein said length is half of the wavelength of said microwave signal.

27. An optical signal processing apparatus according to claim 24, wherein the application direction of the magnetic field is substantially perpendicular to said strip line.