Device for Generating and Modulating a High-Frequency Signal

• US 20080310464A1
• Filed: 07/23/2005
• Published: 12/18/2008
• Est. Priority Date: 08/03/2004
• Status: Abandoned Application

• Current Assignee: Deutsche Telekom AG
• Original Assignee: Deutsche Telekom AG
• Inventors: Schneider, Thomas
• Application Number:
  US11/659,655
• Publication Number:
  US 20080310464A1
• Time in Patent Office: Days
• US Class Current: 372/22
• CPC Class Codes: H01S 3/0085 Modulating the output, i.e. the laser beam is modulated outside the laser cavity
• CPC Class Codes: H01S 3/06754 Fibre amplifiers H01S3/06708 takes precedence
• CPC Class Codes: H01S 3/094096 Multi-wavelength pumping
• CPC Class Codes: H01S 3/302 in an optical fibre
• CPC Class Codes: H04B 10/2575 Radio-over-fibre, e.g. radio frequency signal modulated onto an optical carrier
• CPC Class Codes: H04B 2210/006 Devices for generating or processing an RF signal by optical means

Abstract

A device and method involving a plurality of lasers for generating and modulating a tunable, high-frequency signal for a wireless communication system, including an optical waveguide, may be produced using standard components of optical communication technology. A signal source may be provided which generates an optical signal and is disposed on one side of the optical waveguide. At least one means is provided for generating harmonic waves of this signal, which propagate as frequency mix in the optical waveguide. Two pump lasers are provided for the injection of pump waves on an opposite side of the optical waveguide, which are adapted so that together they amplify two harmonic waves of the frequency mix by stimulated Brillouin scattering. The rest of the harmonic waves are attenuated by damping in the optical waveguide. The two amplified harmonic waves are superposed in a photo element in heterodyne fashion and generate the RF signal.

Claims

1-26. -26. (canceled)

27. A device having a plurality of lasers for generating and modulating a high-frequency signal for a wireless communication network, having an optical waveguide, wherein

a) a signal source is provided, which generates an optical signal and is disposed on one side of the optical waveguide;

b) at least one means is provided, which generates harmonic waves in the optical waveguide that propagate as frequency mix;

c) two pump lasers are provided to inject a signal on an opposite side of the optical waveguide, which are adapted in such a way that, together, they amplify two harmonic waves of the frequency mix by stimulated Brillouin scattering, and the rest of the harmonic waves is attenuated by damping in the optical waveguide.

28. The device of claim 27, wherein the optical signal source is designed as a signal laser generating an optical signal having a constant wavelength.

29. The device of claim 27, wherein the optical signal source is designed as one of a broadband coherent source, a Fabry-Perot laser, a broadband non-coherent source, a photodiode, and an erbium-doped fiber amplifier.

30. The device of claim 27, wherein the means is an optical modulator, which is operated in a range of its non-linear characteristic curve and is designed as controllable by a generator, the modulator being disposed between the signal laser and the optical waveguide.

31. The device of claim 30, wherein a generator is coupled to the pump lasers in such a way that it allows an adjustment of the frequency of the high-frequency signal.

32. The device of claim 29, wherein a polarizer is provided between the modulator and one of the signal source and the signal laser.

33. The device of claim 27, wherein the optical modulator is designed as a Mach-Zehnder modulator.

34. The device of claim 27, wherein the optical modulator is designed as an electro-absorption modulator.

35. The device of claim 27, wherein the means is one of the signal source and the signal laser, which is triggered in the non-linear range of its characteristic curve and generates the required harmonic waves itself.

36. The device of claim 27, wherein each of the pump lasers has an output signal having a frequency that is higher, by the frequency shift of the Brillouin scattering in the utilized optical waveguide, than the respective sideband to be amplified, and the pump lasers are dimensioned such that the output of their two pump waves leads to an amplification of sidebands in the optical waveguide.

37. The device of claim 27, wherein the outputs of the two pump lasers are combined via a coupler at whose output a circulator is connected.

38. The device of claim 27, wherein one of a photo element and a photodiode is provided, which is designed in such a way that heterodyne superpositioning of the two amplified harmonic waves is produced, its output current following a beat frequency formed by the amplified harmonic waves and corresponding to an RF frequency.

39. The device of claim 38, wherein one of an antenna and an antenna amplifier is connected to one output of the one of photo element and photodiode.

40. The device of claim 38, wherein the one of photo element and photodiode is connected to an output of the circulator.

41. The device of claim 40, wherein the circulator is connected to the one of photo element and photodiode via an optical transmission fiber having a length in a kilometer range.

42. The device of claim 27, wherein both the signal laser and the pump lasers have a laser light having a wavelength in the C band of optical telecommunications.

43. The device of claim 27, wherein the optical waveguide is designed as a glass fiber.

44. The device of claim 43, wherein the optical waveguide is designed as a highly non-linear fiber.

45. The device of claim 43, wherein the optical waveguide is designed as micropatterned fiber.

46. The device of claim 43, wherein the optical waveguide is a standard single mode glass fiber.

47. A method for generating a high-frequency signal via an optical waveguide for a wireless communication system, comprising:

an injection of a frequency mix encompassing harmonic waves at one end of the optical waveguide, and by an injection of two pump waves at the other end of the optical waveguide, the pump waves in each case amplifying a harmonic wave by stimulated Brillouin scattering, while the other harmonic waves are attenuated by optical damping in the optical waveguide.

48. The method of claim 47, comprising heterodyne superpositioning of the two amplified harmonic waves.

49. The method of claim 47, comprising one of a modulation and an additional modulation, using useful information superposed onto at least one of the harmonic waves.

50. The method of claim 49, wherein the useful information is superposed onto the harmonic waves by a modulation of a signal laser.

51. The method of claim 49, wherein the useful information is superposed onto one of the harmonic waves by a modulation of a pump laser.

52. The method of claim 47, wherein useful information is superposed onto the harmonic waves by an additional modulation of the generator.