公开(公告)号：CA2315989C

公开(公告)日：2004-10-05

申请号：CA2315989

申请日：2000-08-14

Applicant: LUCENT TECHNOLOGIES INC

Inventor： HUNZIKER GUIDO HERMANN ,  FEULNER MATTHIAS RICHARD ,  ZHOU JIANHUI ,  WERNER DIETER ,  TEICHMANN BERND

IPC: H01S3/10 ,  H01S3/06 ,  H01S3/13 ,  H01S3/131 ,  H04B10/17 ,  H04B10/29 ,  H04J14/00 ,  H04J14/02

Abstract: In an optically amplified wavelength division multiplexed (WDM) system having a WDM signal comprising a plurality of optical channels, the per- channel gain of the optical channels is kept relatively constant despite changes in input power at the optical amplifier, such as when individual optical channels of the WDM signal are added and dropped. More specifically, gain of an optical amplifier is controlled by controlling the amount of pump power supplied to the optica l amplifier as a function of changes in input power which are measured in a fe ed- forward monitoring path. The amount of pump power for effecting gain control is adjusted according to a scaled relationship to the measured input power of t he optical amplifier. By controlling the pump power directly in response to changes in input power, gain of the optical amplifier can be controlled within a sub- microsecond time scale from the time that a change in input power is detecte d. Moreover, by maintaining relatively constant per-channel gain in an amplifi ed WDM signal despite changes in input power at the optical amplifier, pow er excursions are substantially reduced in surviving optical channels of the WD M signal, i.e., those at the output of the optical amplifier.

公开(公告)号：DE69801663T2

公开(公告)日：2002-06-20

申请号：DE69801663

申请日：1998-10-13

Applicant: LUCENT TECHNOLOGIES INC

Inventor： MOELLER LOTHAR BENEDICT ERHARD ,  TEICHMANN BERND

IPC: H04B10/564 ,  H04J14/00 ,  H04J14/02 ,  H04B10/152

Abstract: The present invention generally relates to the field of optical transmission and particularly to a method and an apparatus for controlling the optical power of an optical transmission signal in wavelength division multiplex optical transmission system (WDM system). It is known to add one additional channel to the optical transmission signal of WDM systems, for controlling the power of the optical transmission signal. The optical power of the control channel is controlled to keep the total optical power of the optical transmission signal constant, e. g., if a channel of the optical transmission signal fails, the optical power of the control channel is increased. After surpassing a certain power level the optical signal of the control channel is reflected form the optical fibre because of a non linear effect known as Stimulated Brillouin Scattering (BSS). The present invention avoids this disadvantage by spreading the power density spectrum of the optical control signal.