Multi-channel optical transceiver

• US 20010043379A1
• Filed: 05/16/2001
• Published: 11/22/2001
• Est. Priority Date: 05/16/2000
• Status: Active Grant

• Current Assignee: CommWorks Solutions, LLC (IP Investments Group LLC)
• Original Assignee: Airfiber, Inc.
• Inventors: Alwan, James J., Chan, Victor J., Bloom, Scott H.
• Granted Patent: US 6,490,067 B2
• Time in Patent Office: Days
• US Class Current: 398/128
• CPC Class Codes: H04B 10/1125 using a single common optical path
• CPC Class Codes: H04B 10/2587 using a single light source for multiple stations

Abstract

An optical transceiver such as used, for example, in a wireless optical network (WON), includes multiple laser sources including a first laser source configured to transmit a first output channel beam having a first optical characteristic and at least a second laser source configured to transmit a second output channel beam having a second optical characteristic; multiple detectors including a first detector configured to detect a first input channel beam having the first optical characteristic and at least a second detector configured to detect a second input channel beam having the second optical characteristic; and multiple apertures including a first aperture through which the first output channel beam and the second input channel beam pass and a second aperture through which the second output channel beam and the first input channel beam pass.

Claims

1. An optical transceiver comprising:

a plurality of laser sources including a first laser source configured to transmit a first output channel beam having a first optical characteristic and at least a second laser source configured to transmit a second output channel beam having a second optical characteristic;

a plurality of detectors including a first detector configured to detect a first input channel beam having the first optical characteristic and at least a second detector configured to detect a second input channel beam of the second optical characteristic; and

a plurality of apertures including a first aperture through which the first output channel beam and the second input channel beam pass and a second aperture through which the second output channel beam and the first input channel beam pass.

2. The transceiver of

claim 1

wherein the first optical characteristic comprises a first wavelength and the second optical characteristic comprises a second wavelength different from the first wavelength.

3. The transceiver of

claim 2

wherein a difference between the first wavelength and the second wavelength is about 50 nanometers or greater.

4. The transceiver of

claim 2

wherein the first wavelength is 830 nanometers and the second wavelength is 785 nanometers, or vice versa.

5. The transceiver of

claim 2

wherein at least one of the wavelengths is between 1530 and 1570 nanometers.

6. The transceiver of

claim 1

wherein the first optical characteristic comprises a first polarization and the second optical characteristic comprises a second polarization different from the first polarization.

7. The transceiver of

claim 6

wherein the first polarization comprises transverse electric polarization and the second polarization comprises transverse magnetic polarization, or vice versa.

8. The transceiver of

claim 1

wherein at least one of the laser sources comprises a laser diode.

9. The transceiver of

claim 1

wherein at least one of the laser sources comprises a gas laser.

10. The transceiver of

claim 1

wherein at least one of the laser sources comprises a fiber laser.

11. The transceiver of

claim 1

wherein at least one of the laser sources comprises a diode-pumped solid state (DPSS) laser.

12. The transceiver of

claim 1

wherein at least one of the laser sources comprises a laser diode that emits an output field that is one of substantially transverse electric and substantially transverse magnetic.

13. The transceiver of

claim 1

wherein at least one of the detectors comprises a photodiode.

14. The transceiver of

claim 1

wherein at least one of the detectors comprises an avalanche photodiode and a bandpass filter.

15. The transceiver of

claim 1

wherein at least one of the detectors comprises an avalanche photodiode and a polarizer.

16. The transceiver of

claim 15

wherein the polarizer comprises one of a transverse electric polarizer and a transverse magnetic polarizer.

17. The transceiver of

claim 1

wherein at least one of the apertures comprises a lens.

18. The transceiver of

claim 17

wherein the lens comprises a plano aspheric lens.

19. The transceiver of

claim 17

wherein the lens has a diameter of about 75 mm.

20. The transceiver of

claim 1

further comprising a plurality of beamsplitters including a first beamsplitter associated with the first aperture and a second beamsplitter associated with the second beamsplitter.

21. The transceiver of

claim 20

wherein each beamsplitter differentiates between the first and second optical characteristics.

22. The transceiver of

claim 20

wherein at least one of the beamsplitters comprises an optical highpass filter.

23. The transceiver of

claim 22

wherein the optical highpass filter comprises a dichroic mirror.

24. The transceiver of

claim 20

wherein at least one of the beamsplitters comprises a polarizing beamsplitter.

25. The transceiver of

claim 20

wherein at least one beamsplitter passes beams of the first optical characteristic and reflects beams of the second optical characteristic.

26. The transceiver of

claim 20

wherein each of the plurality of beamsplitters passes beams of the first optical characteristic and reflects beams of the second optical characteristic.

27. The transceiver of

claim 20

wherein at least one beamsplitter passes beams of the first optical characteristic and reflects beams of the second optical characteristic and at least another beamsplitter passes beams of the second optical characteristic and reflects beams of the first optical characteristic.

28. The transceiver of

claim 20

wherein the first output channel beam passes through the first beamsplitter to the first aperture and the second input channel beam is reflected by the first beamsplitter to the second detector.

29. The transceiver of

claim 20

wherein the second output channel beam is reflected by the second beamsplitter to the second aperture and the first input channel beam passes through the second beamsplitter to the first detector.

30. The transceiver of

claim 1

further comprising:

a third laser source configured to transmit a third output channel beam having a third optical characteristic; and

a third detector configured to detect a third input channel beam of the third optical characteristic.

31. The transceiver of

claim 1

further comprising at least two beamsplitters each configured to differentiate between the first and second optical characteristic;

and wherein the laser sources, detectors and beamsplitters are arranged relative to each other such that, when the transceiver is operating, the first output channel beam will be passed and the second input channel beam will be reflected by a common beamsplitter.

32. The transceiver of

claim 1

further comprising at least two beamsplitters each configured to differentiate between the first and second optical characteristic;

and wherein the laser sources, detectors and beamsplitters are arranged relative to each other such that, when the transceiver is operating, the first input channel beam will be passed and the second output channel beam will be reflected by a common beamsplitter.

33. An optical transceiver comprising:

a plurality of dichroic mirrors, each dichroic mirror configured to pass a beam of a first wavelength and reflect a beam of a second wavelength;

a plurality of laser sources including a first laser source arranged to transmit a first output channel beam of the first wavelength through a first dichroic mirror and a second laser source arranged to transmit a second output channel beam of the second wavelength that is reflected by a second dichroic mirror;

a plurality of photodetectors including a first photodetector configured to detect a first input channel beam of the second wavelength reflected by the first dichroic mirror and a second photodetector configured to detect a second input channel beam of the first wavelength passed by the second dichroic mirror; and

a plurality of lenses including a first lens arranged to focus the first output channel beam and the first input channel beam and a second lens arranged to focus the second output channel beam and the second input channel beam.

34. The transceiver of

claim 33

wherein the first and second lenses are physically separated to increase eye safety.

35. The transceiver of

claim 34

wherein the physical separation between the first and second lenses is about 25 millimeters or greater.

36. The transceiver of

claim 33

wherein each of the first and second lenses have a physical dimension that increases eye safety.

37. The transceiver of

claim 36

wherein each of the first and second lenses have a diameter of about 75 millimeters.

38. An optical transceiver comprising:

a laser source configured to transmit an output channel beam having a first optical characteristic;

a photodetector configured to detect an input channel beam having a second optical characteristic different from the first optical characteristic;

an aperture through which the output channel beam and the input channel beam pass; and

a beamsplitter, arranged in an optical path of the aperture and the laser source, and configured to pass the output channel beam from the laser source to the aperture and to reflect the input channel beam from the aperture to the photodetector.

39. The transceiver of

claim 38

wherein the first and second optical characteristics comprise different wavelengths.

40. The transceiver of

claim 38

wherein the first and second optical characteristics comprise different polarizations.

41. A wireless optical communication method comprising:

using a first aperture to transmit a first output channel beam having a first optical characteristic and to receive a first input channel beam of a second optical characteristic different from the first optical characteristic; and

using a second aperture to transmit a second output channel beam having the second optical characteristic and to receive a second input channel beam of the first optical characteristic.

42. The method of

claim 41

further comprising using at least one beamsplitter to differentiate between the first and second optical characteristics.

43. The method of

claim 41

wherein the first and second optical characteristics comprise different wavelengths.

44. The method of

claim 41

wherein the first and second optical characteristics comprise different polarizations.

45. The method of

claim 41

further comprising impressing data on at least one of the first and second output channel beams.

46. The method of

claim 45

wherein impressing data on at least one of the output channel beams comprises applying on/off keying.

47. The method of

claim 45

wherein impressing data on at least one of the output channel beams comprises applying phase-shift keying.

48. The method of

claim 45

wherein impressing data on at least one of the output channel beams comprises applying pulse-position modulation.

49. The method of

claim 45

wherein impressing data on at least one of the output channel beams comprises applying frequency-shift keying.

50. An optical transceiver comprising:

a plurality of laser sources including a first laser source configured to transmit a first output channel beam having a first optical characteristic and at least a second laser source configured to transmit a second output channel beam having a second optical characteristic;

a plurality of detectors including a first detector configured to detect a first input channel beam having the first optical characteristic and at least a second detector configured to detect a second input channel beam of the second optical characteristic; and

a plurality of apertures including a first aperture through which the first and second output channel beams pass and a second aperture through which the first and second input channel beams pass.

51. A wireless optical network comprising a plurality of optical transceivers, each optical transceiver being in communication with at least one other optical transceiver, wherein at least two of the optical transceivers each comprises:

a plurality of laser sources including a first laser source configured to transmit a first output channel beam having a first optical characteristic and at least a second laser source configured to transmit a second output channel beam having a second optical characteristic;

a plurality of detectors including a first detector configured to detect a first input channel beam having the first optical characteristic and at least a second detector configured to detect a second input channel beam of the second optical characteristic; and

a plurality of apertures including a first aperture through which the first output channel beam and the second input channel beam pass and a second aperture through which the second output channel beam and the first input channel beam pass.