Patent ID: 6570695
Filing Date: 2003-05-27
Classification: H04B

Abstract:
In a method for generating an error signal in connection with the coherent heterodyne reception of lightwaves wherein:an information lightwave (1) is relayed via a receiving telescope (2) and an optomechanical receiver means (19) to a deflection means (5) including a first lightwave fiber (7) having a front face (71) with a center (72), light of a local laser (12) is fed via a second lightwave fiber (13) to the information ligthwave (1) to be overlayed on the information lightwave, the information lightwave is split into two beam portions by a beam splitter (6) after having been overlayed with the light of the local laser (12), these beam portions are respectively relayed via a further respective lightwave fiber (8, 9) to a detectors (10, 11) for the generation of at least one error signal Sr, the deflection means (5) and the optomechanical receiver means (19) become active in a focusing area of the front face (71) of the first lightwave fiber (7), an improved method of focusing information lightwave (1) to the front face (71) of the first lightwave fiber (7) comprising the steps of: providing optomechanical receiver means (19) including a fine alignment mechanism (3) and a lens (4); focusing the information lightwave (1) at the front face (71) by means of the optomechanical receiver means (19) which includes the fine alignment mechanism (3) and the lens (4); providing a computer regulator (8) for movement of at least the lens (4) of the optomechanical receiver means (19); and, moving the computer regulator (18) responsive to at least one error signal Sr to cause a focusing spot (22) of the information lightwave (1) to be focused on the center (72) of the front face (71) of first lightwave fiber (7).