| US 7,589,889 B2 | ||
| Transient optical power suppressing apparatus, method, and network | ||
| Paul Lundquist, San Jose, Calif. (US); Marc Levesque, San Jose, Calif. (US); and Denis Zaccarin, San Jose, Calif. (US) | ||
| Assigned to Ciena Corporation, Linthicum, Md. (US) | ||
| Filed on Jul. 16, 2008, as Appl. No. 12/174,351. | ||
| Application 12/174351 is a division of application No. 10/855385, filed on May 28, 2004, granted, now 7,483,205. | ||
| Claims priority of provisional application 60/500241, filed on Sep. 05, 2003. | ||
| Claims priority of provisional application 60/473917, filed on May 29, 2003. | ||
| Prior Publication US 2008/0273876 A1, Nov. 06, 2008 | ||
| Int. Cl. H04B 10/17 (2006.01); G02B 6/26 (2006.01) | ||
| U.S. Cl. 359—341.3 | 9 Claims |
| 1. An apparatus for suppressing optical power transients, comprising:
a variable optical attenuator receiving an input optical signal and outputting an output optical signal;
an optical power sensing element optically coupled to the input optical signal, said optical power sensing element sensing
a portion of the input optical signal and outputting a signal indicative of input optical power of the input optical signal;
and
a feedforward loop controller operatively coupled to said variable optical attenuator and to said optical power sensing element;
said feedforward control loop providing feedforward control of said variable optical attenuator to reduce optical power transients
of the input optical signal and maintain a substantially constant output power based on the signal indicative of the input
optical power and a reference value;
said variable optical attenuator having a default opaque state in which the input optical signal is substantially attenuated
when power is not being supplied to said variable optical attenuator; and
said feedforward control loop providing control of said variable optical attenuator to reduce optical power transients and
maintain a substantially constant output power based on the input optical power measured by said optical power sensing element
and a reference value, wherein said reference value comprises a value proportional to one of a desired output power level
and a desired optical attenuation, and wherein said reference value is adjustable by a user.
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