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Two-dimensional photonic crystal optical multiplexer/demultiplexer using boundary reflection

Foreign code F110005159
File No. A112-32US
Posted date Aug 24, 2011
Country United States of America
Application number 53751303
Gazette No. 20060051014
Gazette No. 7224862
Date of filing Dec 5, 2003
Gazette Date Mar 9, 2006
Gazette Date May 29, 2007
International application number JP2003015636
International publication number WO2004053549
Date of international filing Dec 5, 2003
Date of international publication Jun 24, 2004
Priority data
  • P2002-355632 (Dec 6, 2002) JP
  • P2003-057245 (Mar 4, 2003) JP
  • 2003WO-JP15636 (Dec 5, 2003) WO
Title Two-dimensional photonic crystal optical multiplexer/demultiplexer using boundary reflection
Abstract (US7224862)
In an in-plane heterostructure photonic crystal in which vacancies 32 are periodically arranged in each of forbidden band zones 301, 302, with different cycle distances, a waveguide 33 is formed passing through all the forbidden band zones and point-like defects 341, 342, . . . are formed in each of the forbidden band zones.
Since, of all light propagating through the waveguide from the light introduction/take-out section 36 and having the frequency 52 demultiplexed from the predetermined point-like defect, the wavelength of light passing through the predetermined point-like defect is not included in transmission bands 51 of the waveguide in the adjacent forbidden band zone, so that the light is reflected on the boundaries 351 and 352 between forbidden band zones and introduced into the point-like defect.
Thereby, the demultiplexing efficiency of light is improved.
The same applies to the multiplexing efficiency.
Scope of claims [claim1]
1. A two-dimensional photonic crystal optical multiplexer/demultiplexer using boundary reflection, comprising:
a) a slab-shaped body;
b) plural modified refractive index areas arranged periodically in the body, each having a refractive index different from that of the body;c) a waveguide formed by creating defects of the modified refractive index areas in a linear arrangement, the end of which is located on an end of the body;d) a point-like defect formed by creating a defect of modified refractive index area or areas in the vicinity of the waveguide;
and
e) a first reflecting section provided at an end of the waveguide, for reflecting light having wavelength equal to the resonant wavelength of the point-like defect by connecting another two-dimensional photonic crystal not transmitting light with the wavelength to the end of the body.
[claim2]
2. The two-dimensional photonic crystal optical multiplexer/demultiplexer using boundary reflection according to claim 1, wherein the distance between the first reflecting section and the point-like defect is set so that the phase difference between light having wavelength equal to the resonant wavelength of the point-like defect and reflected on the point-like defect, and light with the same wavelength passing over the point-like defect and reflected on the first reflecting section is pi .
[claim3]
3. The two-dimensional photonic crystal optical multiplexer/demultiplexer using boundary reflection according to claim 1, wherein the distance between the first reflecting section and the point-like defect is set so that the phase difference between light having wavelength equal to the resonant wavelength of the point-like defect and introduced into the waveguide from this point-like defect, and light with the same wavelength and reflected on the first reflecting section is 0.
[claim4]
4. The two-dimensional photonic crystal optical multiplexer/demultiplexer using boundary reflection according claim 1, wherein a second reflecting section reflecting at least part of light having wavelength equal to the resonant wavelength is formed at the end of the waveguide opposite to the first reflecting section.
[claim5]
5. The two-dimensional photonic crystal optical multiplexer/demultiplexer using boundary reflection according to claim 4, wherein the distance between the second reflecting section and the point-like defect is set so that the phase difference between light with the resonant wavelength in the point-like defect and introduced from the second reflecting section side, and light having wavelength equal to the same wavelength, introduced from the second reflecting section, reflected on the point-like defect, and further reflected on the second reflecting section is 0.
[claim6]
6. The two-dimensional photonic crystal optical multiplexer/demultiplexer using boundary reflection according to claim 1, wherein light having wavelength equal to the resonant wavelength of the point-like defect is totally reflected on the first reflecting section, and the ratio Qp/Qv is set in the range of 1.4 to 2.8 where Qp is the coupling coefficient between the point-like defect and the waveguide, and Qv is the coupling coefficient between the point-like defect and the air.
[claim7]
7. The two-dimensional photonic crystal optical multiplexer/demultiplexer using boundary reflection according to claim 6, wherein the ratio of Qp/Qv is set to 2.
[claim8]
8. A two-dimensional photonic crystal optical multiplexer/demultiplexer using boundary reflection, comprising:
a) a slab-shaped body;
b) two or more forbidden band zones provided in the body;c) plural modified refractive index areas provided in each of the forbidden band zones, each area having a refractive index different from that of the body, and periodically arranged in the body in a different cycle distance from each other in each of the forbidden band zones;
and
d) a waveguide formed by creating defects of modified refractive index areas in a linear arrangement in the respective forbidden band zones, and passing through all the forbidden band zones;e) a point-like defect created in the vicinity of the waveguide in each of the forbidden band zones;
and
wherein,f) a part of a waveguide-transmittable wavelength band in each of the forbidden band zone is not included in a waveguide-transmittable wavelength band of all forbidden band zones present on one side of the forbidden band zone, but included in the waveguide-transmittable wavelength band of all forbidden band zones present on the other side of the forbidden band zone;
and
g) the resonant wavelength of the point-like defect created in each of the forbidden band zones is included in the part of the transmission wavelength band.
[claim9]
9. The two-dimensional photonic crystal optical multiplexer/demultiplexer using boundary reflection according to claim 8, wherein the point-like defect is a linear donor-type cluster defect formed by rendering three adjacent modified refractive index areas defective.
[claim10]
10. The two-dimensional photonic crystal optical multiplexer/demultiplexer using boundary reflection according to claim 8, wherein the end of the waveguide of said one side is located on an end of the body, and another two-dimensional photonic crystal not transmitting light having wavelength equal to the resonant wavelength of the point-like defect is connected to the end of the body.
[claim11]
11. The two-dimensional photonic crystal optical multiplexer/demultiplexer using boundary reflection according to claim 8, wherein, the distance between the boundary with the adjacent forbidden band zone on said one side and the point-like defect provided in that forbidden band zone is set so that the phase difference between light having wavelength equal to the resonant wavelength of the point-like defect of the forbidden band zone and reflected on the point-like defect, and light with the same wavelength passing over the point-like defect and reflected on the boundary between the forbidden band zones is pi .
[claim12]
12. The two-dimensional photonic crystal optical multiplexer/demultiplexer using boundary reflection according to claim 8, wherein the distance between the boundary with the adjacent forbidden band zone on said one side and the point-like defect provided in that forbidden band zone is set so that the phase difference between light with the resonant wavelength of the point-like defect of the forbidden band zone, and introduced into the waveguide from this point-like defect, and light with the same wavelength and reflected on the boundary between the forbidden band zones is 0.
[claim13]
13. The two-dimensional photonic crystal optical multiplexer/demultiplexer using boundary reflection according to claim 8, wherein the ratio Qp/Qv is set in the range of 1.4 to 2.8, where Qp is a coupling coefficient between the point-like defect and the waveguide in each of the forbidden band zones and Qv is a coupling coefficient between the point-like defect and the air.
[claim14]
14. The two-dimensional photonic crystal optical multiplexer/demultiplexer using boundary reflection according to claim 13, wherein the ratio of Qp/Qv is set to 2.
  • Inventor, and Inventor/Applicant
  • NODA SUSUMU
  • ASANO TAKASHI
  • JAPAN SCIENCE AND TECHNOLOGY AGENCY
IPC(International Patent Classification)
Reference ( R and D project ) CREST Function Evolution of Materials and Devices based on Electron/Photon Related Phenomena AREA
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