Claims
- 1. A light modulating system, comprising:
a first source of radiation for providing radiation within the frequency range of approximately 300 gighertz to 30 terahertz.; a modulator receptive to the radiation and an information signal to generate modulated radiation; a second source of radiation for providing transmission radiation having a wavelength suitable for transmission over fiber optics or use in digital electrical switches or optical switches; and a signal mixer receptive of the modulated radiation and the transmission radiation to generate a modulated transmission radiation having a frequency of a sum or a difference of the modulated radiation and the transmission radiation.
- 2. The light modulating system of claim 1 wherein the modulator is operable at ambient temperature.
- 3. The light modulating system of claim 1 wherein the first source comprises an optically-pumped far infrared laser, a directly multiplied source, a photo-mixer, or a quantum cascade laser.
- 4. The light modulating system of claim 1 wherein the modulator comprises a sideband-generator.
- 5. The light modulating system of claim 4 wherein the sideband-generator comprises:
a coupling structure; and an ultra-high-frequency Schottky diode disposed at the coupling structure wherein the radiation and the information signal are coupled to the ultra-high-frequency Schottky diode, mixing therein wherein the modulated radiation is coupled out of the diode.
- 6. The light modulating system of claim 4 wherein the sideband-generator comprises:
a coupling structure; and an ultra-high-frequency high electron mobility transistor disposed at the coupling structure wherein the radiation and the information signal are coupled to the ultra-high-frequency high electron mobility transistor, mixing therein wherein the modulated radiation is coupled out of the diode.
- 7. The light modulating system of claim 1 wherein the wavelength suitable for transmission over fiber optics comprises a wavelength of approximately 1.5 μm or other suitable communications wavelength for supplying broad band signals to either an optical fiber telecommunications system or to digital electrical or optical switches.
- 8. The light modulating system of claim 1 wherein the nonlinear optical mixing subsystem includes a crystal comprised of ZnTe, DAST®, ZnGeP2 or GaP.
- 9. The light modulating system of claim 1 further comprising a terahertz filter acting on the modulated radiation to remove un-modulated radiation therein.
- 10. The light modulating system of claim 9 wherein the terahertz filter comprises an etalon diplexer or an inverse Fabry-Perot etalon.
- 11. The light modulating system of claim 1 further comprising:
a transmission filter acting on the modulated transmission radiation to remove un-modulated radiation at the wavelength suitable for transmission over fiber optics in the modulated transmission radiation.
- 12. The light modulating system of claim 10 further comprising:
a transmission filter acting on the modulated transmission radiation to remove un-modulated radiation at the wavelength suitable for transmission over fiber optics in the modulated transmission radiation.
- 13. A communications transmission system comprising:
a first radiation source generating a carrier signal at a first prescribed frequency; a modulator receptive of the carrier signal and an information signal to generate thereby a modulated carrier signal; a second radiation source generating a transmission signal at a second prescribed frequency; and a signal mixer receptive of the modulated carrier signal and the transmission signal to generate a frequency shifted transmission signal having a frequency equal to the sum of the frequency of the modulated carrier signal and the frequency of the transmission signal or equal to the difference between the frequency of the transmission signal and the frequency of the modulated carrier signal.
- 14. The communications transmission system as set forth in claim 13 wherein the first radiation source comprises a source of coherent radiation.
- 15. The communications transmission system as set forth in claim 14 wherein the first radiation source comprises a source of radiation within the frequency range of approximately 300 gighertz to 30 terahertz.
- 16. The communications transmission system as set forth in claim 15 wherein the first radiation source comprises an optically-pumped far infrared laser, a directly multiplied source, a photo-mixer, or a quantum cascade laser.
- 17. The communications transmission system as set forth in claim 13 wherein the second radiation source comprises a source of radiation generating a transmission signal having a frequency suitable for transmission over an optical network.
- 18. The communications transmission system as set forth in claim 17 wherein the second radiation source comprises a laser.
- 19. The communications transmission system as set forth in claim 13 wherein the signal mixer comprises a nonlinear mixer or subsystem.
- 20. The communications transmission system as set forth in claim 19 wherein the nonlinear mixer comprises an optical crystal.
- 21. The communications transmission system as set forth in claim 13 wherein the modulator comprises a sideband generator.
- 22. The communications transmission system as set forth in claim 21 wherein the sideband generator comprises:
a coupling structure; and a diode disposed at the coupling structure wherein the carrier signal and the information signal are coupled to the diode, mixing therein wherein a modulated carrier signal is thereby coupled out of the diode.
- 23. The communications transmission system as set forth in claim 22 wherein the diode comprises a Schottky diode.
- 24. The communications transmission system as set forth in claim 21 further comprising an impedance matching device matching the impedance of the sideband generator to the impedance of the second radiation source.
- 25. The communications transmission system as set forth in claim 21 wherein the sideband generator comprises:
a coupling structure; and a transistor disposed at the coupling structure wherein the carrier signal and the information signal are coupled to the diode, mixing therein wherein a modulated carrier signal is thereby coupled out of the diode.
- 26. The communications transmission system as set forth in claim 25 wherein the transistor comprises an ultra-high-frequency high electron mobility transistor.
- 27. The communications transmission system as set forth in claim 21 wherein the diode comprises a reflective phase modulator disposed at the coupling structure to couple the carrier signal and the information signal to the sideband generator, the information signal comprising a sideband signal.
- 28. The communications transmission system as set forth in claim 20 wherein the optical crystal comprises ZnTe, GaP, ZnGeP2 or DAST®.
- 29. The communications transmission system as set forth in claim 13 further comprising a first filter receptive of the modulated carrier signal for filtering unmodulated portions of the carrier signal from the modulated carrier signal.
- 30. The communications transmission system as set forth in claim 29 wherein the first filter comprises an etalon.
- 31. The communications transmission system as set forth in claim 30 wherein the etalon comprises a Silicon etalon diplexer having a prescribed thickness.
- 32. The communications transmission system as set forth in claim 31 wherein the prescribed thickness of the etalon is a function of the frequency of the carrier signal and the frequency range of the information signal.
- 33. The communications transmission system as set forth in claim 30 wherein the etalon comprises an inverse Fabry-Perot etalon.
- 34. The communications transmission system as set forth in claim 13 further comprising a second filter receptive of the frequency shifted transmission signal for filtering unshifted portions of the transmission signal from the frequency shifted transmission signal.
- 35. The communications transmission system as set forth in claim 13 wherein the frequency shifted transmission signal comprises a signal shifted up in frequency.
- 36. The communications transmission system as set forth in claim 22 wherein the coupling structure comprises a feedhorn, a lens or a waveguide.
- 37. The communications transmission system as set forth in claim 25 wherein the coupling structure comprises a feedhorn, a lens or a waveguide.
- 38. The communications transmission system as set forth in claim 13 wherein the modulator is operable at ambient temperature.
- 39. The communications transmission system as set forth in claim 18 wherein the laser comprises a distributed feedback laser.
- 40. The communications transmission system as set forth in claim 17 wherein the frequency suitable for transmission over an optical network comprises about 200 terahertz or other suitable communications frequencies.
- 41. A method of increasing the amount of information transmitted over a communications channel, the method comprising:
modulating a carrier signal having a first prescribed frequency with an information signal having a prescribed first bandwidth, generating thereby a modulated carrier signal having a second prescribed bandwidth; and mixing a transmission signal having a second prescribed frequency with the modulated carrier signal, generating thereby a frequency shifted transmission signal having a third prescribed bandwidth.
- 42. The method as set forth in claim 41 further comprising filtering the modulated carrier signal to suppress undesired frequencies in the modulated carrier signal.
- 43. The method as set forth in claim 41 further comprising filtering the frequency shifted transmission signal to reduce the presence of undesired frequencies in the frequency shifted transmission signal.
- 44. The method as set forth in claim 41 wherein modulating the carrier signal with an information signal comprises modulating the carrier signal in a sideband generator.
- 45. The method as set forth in claim 41 wherein mixing the transmission signal with the modulated carrier signal comprises mixing the transmission signal with the modulated carrier signal in a nonlinear device or subsystem.
- 46. The method as set forth in claim 41 wherein the communications channel is an optical fiber.
- 47. The method as set forth in claim 41 further comprising filtering the modulated carrier signal to suppress undesired frequencies in the modulated carrier signal or the frequency shifted transmission signal to reduce the presence of undesired frequencies in the converted transmission signal.
- 48. A method of increasing the extinction ratio of a data transmission system, the method comprising:
modulating a carrier signal having a first prescribed frequency with an information signal having a prescribed first bandwidth, generating thereby a modulated carrier signal having a second prescribed bandwidth; mixing a transmission signal having a second prescribed frequency with the modulated carrier signal, generating thereby a frequency shifted transmission signal having a third prescribed bandwidth; and filtering the modulated carrier signal to suppress undesired frequencies in the modulated carrier signal or the frequency shifted transmission signal to reduce the presence of undesired frequencies in the frequency shifted transmission signal.
- 49. The method as set forth in claim 48 wherein modulating the carrier signal with an information signal comprises modulating the carrier signal in a sideband generator.
- 50. The method as set forth in claim 48 wherein mixing the transmission signal with the modulated carrier signal comprises mixing the transmission signal with the modulated carrier signal in a nonlinear mixer or subsystem.
- 51. The communications transmission system as set forth in claim 34 further comprising:
a detector receptive of the frequency shifted transmission signal for detecting the information signal modulating the carrier signal providing thereby as output a signal indicative of the information signal; and a switch receptive of the signal indicative of the information signal for routing the signal indicative of the information signal to one or more-broad bandwidth channels for delivery to a communications network or data system.
- 52. The communications transmission system as set forth in claim 51 wherein the frequency shifted transmission signal is an optical signal.
- 53. The communications transmission system as set forth in claim 51 wherein the carrier signal is an optical signal.
- 54. The communications transmission system as set forth in claim 51 wherein the switch is an electrical switch.
- 55. The communications transmission system as set forth in claim 34 further comprising a switch receptive of the frequency shifted transmission signal for routing the frequency shifted signal to one or more broad bandwidth channels for delivery to a communications network or data system.
- 56. The communications transmission system as set forth in claim 55 wherein the switch is an optical switch.
- 57. The communications transmission system as set forth in claim 55 wherein the transmission signal is an optical signal.
- 58. The communications transmission system as set forth in claim 55 wherein the one or more broad bandwidth signals are optical signals.
- 59. The method as set forth in claim 50 wherein mixing the transmission signal with the modulated carrier signal in a nonlinear mixer or subsystem comprises mixing the transmission signal with the modulated carrier signal in an optical crystal.
- 60. The communications transmission system as set forth in claim 1 wherein the signal mixer comprises a nonlinear mixer or subsystem.
- 61. The communications transmission system as set forth in claim 60 wherein the nonlinear mixer comprises an optical crystal.
- 62. The method as set forth in claim 45 wherein mixing the transmission signal with the modulated carrier signal in a nonlinear device or subsystem comprises mixing the transmission signal with the modulated carrier signal in an optical crystal.
REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/225,882, filed on Aug. 17, 2000 which is incorporated herein by reference.
Provisional Applications (1)
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Number |
Date |
Country |
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60225882 |
Aug 2000 |
US |