Holographic optical devices for transmission of optical signals

• US 6,269,203 B1
• Filed: 05/21/1999
• Issued: 07/31/2001
• Est. Priority Date: 03/17/1999
• Status: Expired due to Term

• Current Assignee: II-VI Delaware, Inc. (Coherent Corp.)
• Original Assignee: Radiant Photonics, Inc.
• Inventors: Liu, Jian, Davies, Brian M., Chen, Ray T.
• Primary Examiner(s): Ullah, Akm E.
• Application Number:
  US09/316,323
• Time in Patent Office: 802 Days
• Field of Search: 385/11-13, 385/19, 385/33, 385/24, 385/37, 359/567, 359/576, 359/629, 359/634, 359/572, 369/103, 369/112.09, 369/112.01, 369/44.14, 369/44.37
• US Class Current: 385/24
• CPC Class Codes: G02B 6/29329 Diffractive elements operating in transmission
• CPC Class Codes: G02B 6/2938 for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM

Abstract

The present invention relates to the transmission of optical signals, and more particularly to wavelength division multiplexers and demultiplexers for optical signals. A wavelength division multiplexer device for use in an optical transmission system comprises a light input, one or more lenses, a substrate, one or more holographic optical elements, and two or more light outputs. The light input, the substrate, and the one or more lenses direct a light beam through the device. The one or more holographic optical elements act as transmission diffraction gratings and spatially separate the input light beam into dispersed light beams. Each light output receives one of the dispersed light beams. Multiple holographic optical elements may be stacked upon one another or separated by a substrate. Additionally, the substrate may comprise edges or parts that are beveled. Finally, the elements of the present invention may be rigidly coupled to each other, without intervening air space.

Claims

1. A wavelength division multiplexer device for use in an optical transmission system, comprising:

a light input that directs an input light beam toward a first lens, wherein said first lens directs said input light beam toward a holographic optical element that acts as a transmission diffraction grating, and wherein said holographic optical element spatially separates said input light beam into two or more dispersed light beams;

a light-transmissive substrate that receives said dispersed light beams from said holographic optical element;

a second lens that receives said dispersed light beams from said substrate; and

two or more light outputs, each of which receives one of said dispersed light beams from said second lens.

2. The device of claim 1 wherein said substrate comprises a first edge and a second edge opposed to said first edge, said second edge comprising a beveled portion, wherein said beveled portion is coupled to a reflective surface.

3. The device of claim 1 wherein said substrate comprises a top part and a bottom part, wherein each of said top part and said bottom part comprises a first edge and a second edge, and wherein said second edge of said top part comprises a beveled portion, and wherein said first edge of said bottom part comprises a beveled portion, and wherein said holographic optical element is disposed between said top part and said bottom part.

4. The device of claim 1 wherein said elements are rigidly coupled to each other, without intervening air space, such that said light input is directly coupled to said first lens, said first lens is directly coupled to said holographic optical element, said holographic optical element is directly coupled to said substrate, said substrate is directly coupled to said second lens, and said light outputs are directly coupled to said second lens.

5. The device of claim 3 wherein said elements are rigidly coupled to each other, without intervening air space, such that said light input is directly coupled to said first lens, said first lens is directly coupled to said top part of said substrate, said top part of said substrate is directly coupled to said holographic optical element, said holographic optical element is directly coupled to said bottom part of said substrate, said bottom part of said substrate is directly coupled to said second lens, and said second lens is directly coupled to said light outputs.

6. The device of claim 1 wherein said second lens is formed as an integral portion of said substrate.

7. The device of claim 1 wherein said holographic optical element further comprises two or more holographic optical elements that act as transmission gratings, wherein said two or more holographic optical elements are stacked upon one another.

8. A wavelength division multiplexer device for use in an optical transmission system, comprising:

a light input that directs an input light beams toward a first lens, wherein said first lens directs said input light beam toward a light-transmissive substrate;

a holographic optical element that receives said input light beam from said substrate, wherein said holographic optical element acts as a transmission diffraction grating, said holographic optical element spatially separates said input light beam into two or more dispersed light beams;

a second lens that receives said dispersed light beams from said holographic optical element; and

two or more light outputs, each of which receives one of said dispersed light beams from said second lens.

9. The device of claim 8 wherein:

said substrate comprises a first edge and a second edge opposed to said first edge, said second edge comprising a beveled portion, wherein said beveled portion is coupled to a reflective surface; and

wherein said elements are rigidly coupled to each other, without intervening air space, such that said light input is directly coupled to said first lens, said first lens is directly coupled to said substrate, said substrate is directly coupled to said holographic optical element, said holographic optical element is directly coupled to said second lens, and said second lens is directly coupled to said light outputs.

10. A wavelength division multiplexer device for use in an optical transmission system, comprising:

a light input that directs an input light beam toward a first lens, wherein said first lens directs said input light beam toward a first holographic optical element that acts as a transmission diffraction grating, and wherein said first holographic optical element spatially separates said input light beam into two or more dispersed light beams;

a transparent substrate that receives said dispersed light beams from said first holographic optical element;

a second holographic optical element that receives and diffracts said dispersed light beams;

a plurality of output lenses that receives said dispersed light beams from said second holographic optical element; and

two or more light outputs, each of which receives one of said dispersed light beams from said plurality of output lenses.

11. An optical transmission system that uses a wavelength division multiplexer, comprising:

a light input that directs an input light beam toward a first lens, wherein said first lens directs said input light beam toward a holographic optical element that acts as a transmission diffraction grating, and wherein said holographic optical element spatially separates said input light beam into two or more dispersed light beams;

a light-transmissive substrate that receives said dispersed light beams from said holographic optical element;

a second lens that receives said dispersed light beams from said substrate; and

two or more light outputs, each of which receives one of said dispersed light beams from said second lens.

12. The system of claim 11 wherein said substrate comprises a first edge and a second edge opposed to said first edge, said second edge comprising a beveled portion, wherein said beveled portion is coupled to a reflective surface.

13. The system of claim 11 wherein said substrate comprises a top part and a bottom part, wherein each of said top part and said bottom part comprises a first edge and a second edge, and wherein said second edge of said top part comprises a beveled portion, and wherein said first edge of said bottom part comprises a beveled portion, and wherein said holographic optical element is disposed between said top part and said bottom part.

14. The system of claim 11 wherein said elements are rigidly coupled to each other, without intervening air space, such that said light input is directly coupled to said first lens, said first lens is directly coupled to said holographic optical element, said holographic optical element is directly coupled to said substrate, said substrate is directly coupled to said second lens, and said light outputs are directly coupled to said second lens.

15. The system of claim 13 wherein said elements are rigidly coupled to each other, without intervening air space, such that said light input is directly coupled to said first lens, said first lens is directly coupled to said top part of said substrate, said top part of said substrate is directly coupled to said holographic optical element, said holographic optical element is directly coupled to said bottom part of said substrate, said bottom part of said substrate is directly coupled to said second lens, and said second lens is directly coupled to said light outputs.

16. The system of claim 11 wherein said second lens is formed as an integral portion of said substrate.

17. The system of claim 11 wherein said holographic optical element further comprises two or more holographic optical elements that act as transmission gratings, wherein said two or more holographic optical elements are stacked upon one another.

18. An optical transmission system that uses a wavelength division multiplexer, comprising:

a light input that directs an input light beams toward a first lens, wherein said first lens directs said input light beam toward a light-transmissive substrate;

a holographic optical element that receives said input light beam from said substrate, wherein said holographic optical element acts as a transmission diffraction grating, said holographic optical element spatially separates said input light beam into two or more dispersed light beams;

a second lens that receives said dispersed light beams from said holographic optical element; and

two or more light outputs, each of which receives one of said dispersed light beams from said second lens.

19. The system of claim 18 wherein:

said substrate comprises a first edge and a second edge opposed to said first edge, said second edge comprising a beveled portion, wherein said beveled portion is coupled to a reflective surface; and

wherein said elements are rigidly coupled to each other, without intervening air space, such that said light input is directly coupled to said first lens, said first lens is directly coupled to said substrate, said substrate is directly coupled to said holographic optical element, said holographic optical element is directly coupled to said second lens, and said second lens is directly coupled to said light outputs.

20. An optical transmission system that uses a wavelength division multiplexer device, comprising:

a light input that directs an input light beam toward a first lens, wherein said first lens directs said input light beam toward a first holographic optical element that acts as a transmission diffraction grating, and wherein said first holographic optical element spatially separates said input light beam into two or more dispersed light beams;

a transparent substrate that receives said dispersed light beams from said first holographic optical element;

a second holographic optical element that receives and diffracts said dispersed light beams;

a plurality of output lenses that receives said dispersed light beams from said second holographic optical element; and

two or more light outputs, each of which receives one of said dispersed light beams from said plurality of output lenses.

21. A method of manufacturing a wavelength division multiplexer device for use in an optical transmission system, comprising:

providing a first lens that receives a light input from an input light beam wherein said first lens directs said input light beam toward a holographic optical element that acts as a transmission diffraction grating, wherein said holographic optical element spatially separates said input light beam into two or more dispersed light beams;

optically coupling a light-transmissive substrate to holographic optical element, said light-transmissive substrate receives said dispersed light beams from said holographic optical element;

optically coupling a second lens to said light-transmissive substrate, said second lens receives said dispersed light beams from said substrate; and

optically coupling two or more light outputs to said second lens, each of said light outputs receives one of said dispersed light beams from said second lens.

22. The method of claim 21 wherein said substrate comprises a first edge and a second edge opposed to said first edge, said second edge comprising a beveled portion, wherein said beveled portion is coupled to a reflective surface.

23. The method of claim 21 wherein said substrate comprises a top part and a bottom part, wherein each of said top part and said bottom part comprises a first edge and a second edge, and wherein said second edge of said top part comprises a beveled portion, and wherein said first edge of said bottom part comprises a beveled portion, and wherein said holographic optical element is disposed between said top part and said bottom part.

24. The method of claim 21 wherein said elements are rigidly coupled to each other, without intervening air space, such that said light input is directly coupled to said first lens, said first lens is directly coupled to said holographic optical element, said holographic optical element is directly coupled to said substrate, said substrate is directly coupled to said second lens, and said light outputs are directly coupled to said second lens.

25. The method of claim 23 wherein said elements are rigidly coupled to each other, without intervening air space, such that said light input is directly coupled to said first lens, said first lens is directly coupled to said top part of said substrate, said top part of said substrate is directly coupled to said holographic optical element, said holographic optical element is directly coupled to said bottom part of said substrate, said bottom part of said substrate is directly coupled to said second lens, and said second lens is directly coupled to said light outputs.

26. The method of claim 21 wherein said second lens is formed as an integral portion of said substrate.

27. The method of claim 21 wherein said holographic optical element further comprises two or more holographic optical elements that act as transmission gratings, wherein said two or more holographic optical elements are stacked upon one another.

28. A method of manufacturing a wavelength division multiplexer device for use in an optical transmission system, comprising:

providing a first lens that receives a light input from an input light beam wherein said first lens directs said input light beam toward a light-transmissive substrate;

optically coupling a holographic optical element to said light-transmissive substrate, said holographic optical element receives said input light beam from said substrate, said holographic optical element acts as a transmission diffraction grating, said holographic optical element spatially separates said input light beam into two or more dispersed light beams;

optically coupling a second lens to said holographic optical element, said second lens receives said dispersed light beams from said holographic optical element; and

optically coupling two or more light outputs to said second lens, each of said light outputs receives one of said dispersed light beams from said second lens.

29. The method of claim 28 wherein:

said substrate comprises a first edge and a second edge opposed to said first edge, said second edge comprising a beveled portion, wherein said beveled portion is coupled to a reflective surface; and

wherein said elements are rigidly coupled to each other, without intervening air space, such that said light input is directly coupled to said first lens, said first lens is directly coupled to said substrate, said substrate is directly coupled to said holographic optical element, said holographic optical element is directly coupled to said second lens, and said second lens is directly coupled to said light outputs.

30. A method of manufacturing a wavelength division multiplexer device for use in an optical transmission system, comprising:

providing a first lens that receives a light input from an input light beam wherein said first lens directs said input light beam toward a first holographic optical element that acts as a transmission diffraction grating, and wherein said first holographic optical element spatially separates said input light beam into two or more dispersed light beams;

optically coupling a transparent substrate to said first holographic optical element, said transparent substrate receives said dispersed light beams from said first holographic optical element;

optically coupling a second holographic optical element to said first holographic optical element, said second holographic optical element receives and diffracts said dispersed light beams;

optically coupling a plurality of output lenses to said second holographic optical element, said output lenses receives said dispersed light beams from said second holographic optical element; and

optically coupling two or more light outputs to said output lenses, each of said light outputs receives one of said dispersed light beams from said plurality of output lenses.

31. A method that uses a wavelength division multiplexer device in an optical transmission system, comprising:

providing a light input that directs an input light beam toward a first lens wherein said first lens directs said input light beam toward a holographic optical element that acts as a transmission diffraction grating, and wherein said holographic optical element spatially separates said input light beam into two or more dispersed light beams;

transmitting said dispersed light beams towards a light-transmissive substrate from said holographic optical element;

receiving said dispersed light beams from said substrate into a second lens; and

receiving into two or more light outputs said dispersed light beams wherein each of said light outputs receives one of said dispersed light beams from said second lens.

32. The method of claim 31 wherein said substrate comprises a first edge and a second edge opposed to said first edge, said second edge comprising a beveled portion, wherein said beveled portion is coupled to a reflective surface.

33. The method of claim 31 wherein said substrate comprises a top part and a bottom part, wherein each of said top part and said bottom part comprises a first edge and a second edge, and wherein said second edge of said top part comprises a beveled portion, and wherein said first edge of said bottom part comprises a beveled portion, and wherein said holographic optical element is disposed between said top part and said bottom part.

34. The method of claim 31 wherein said elements are rigidly coupled to each other, without intervening air space, such that said light input is directly coupled to said first lens, said first lens is directly coupled to said holographic optical element, said holographic optical element is directly coupled to said substrate, said substrate is directly coupled to said second lens, and said light outputs are directly coupled to said second lens.

35. The method of claim 33 wherein said elements are rigidly coupled to each other, without intervening air space, such that said light input is directly coupled to said first lens, said first lens is directly coupled to said top part of said substrate, said top part of said substrate is directly coupled to said holographic optical element, said holographic optical element is directly coupled to said bottom part of said substrate, said bottom part of said substrate is directly coupled to said second lens, and said second lens is directly coupled to said light outputs.

36. The method of claim 31 wherein said second lens is formed as an integral portion of said substrate.

37. The method of claim 31 wherein said holographic optical element further comprises two or more holographic optical elements that act as transmission gratings, wherein said two or more holographic optical elements are stacked upon one another.

38. A method that uses a wavelength division multiplexer device in an optical transmission system, comprising:

providing a light input that directs an input light beams toward a first lens wherein said first lens directs said input light beam toward a light-transmissive substrate;

transmitting said input light beam from said light-transmissive substrate to a holographic optical element wherein said holographic optical element acts as a transmission diffraction grating; and

wherein said holographic optical element spatially separates said input light beam into two or more dispersed light beams;

receiving said dispersed light beams into a second lens that receives from said holographic optical element; and

receiving into two or more light outputs said dispersed light beams wherein each of said light outputs receives one of said dispersed light beams from said second lens.

39. The method of claim 38 wherein:

said substrate comprises a first edge and a second edge opposed to said first edge, said second edge comprising a beveled portion, wherein said beveled portion is coupled to a reflective surface; and

wherein said elements are rigidly coupled to each other, without intervening air space, such that said light input is directly coupled to said first lens, said first lens is directly coupled to said substrate, said substrate is directly coupled to said holographic optical element, said holographic optical element is directly coupled to said second lens, and said second lens is directly coupled to said light outputs.

40. A method that uses a wavelength division multiplexer device in an optical transmission system, comprising:

providing a light input that directs an input light beam toward a first lens wherein said first lens directs said input light beam toward a first holographic optical element that acts as a transmission diffraction grating, and wherein said first holographic optical element spatially separates said input light beam into two or more dispersed light beams;

transmitting said dispersed light beams towards a transparent substrate from said first holographic optical element;

transmitting said dispersed light beams from said first holographic optical element to a second holographic optical element that receives and diffracts said dispersed light beams;

receiving said dispersed light beams from said second holographic optical element in to a plurality of output lenses; and

receiving into two or more light outputs said dispersed light beams wherein each of said light outputs receives one of said dispersed light beams from said plurality of output lenses.