Optical transmission system having optimized filter wavelength offsets
View Patent ↗An optical transmission system having optical transmit and receive filters having passbands adjusted or selected for opposite and equal wavelength offsets from the optical wavelength of a carrier or the channel center wavelength.
1. An optical transmission system, comprising:
an optical transmitter including a light generator for generating a transmit signal having a carrier wavelength and an optical transmit filter for filtering said transmit signal at a transmit wavelength offset with respect to said carrier wavelength; and
an optical receiver for receiving said filtered transmit signal through a link, the receiver including an optical receive filter for filtering said received signal at a receive wavelength offset opposite and equal said transmit wavelength offset with respect to said carrier wavelength.
2. The system of claim 1 , wherein:
the optical receiver further includes an error estimator for estimating an error rate for said filtered received signal; and
the receive filter uses said estimated error rate for tuning said receive wavelength offset for minimizing said estimated error rate.
3. The system of claim 1 , wherein:
the optical receiver further includes an error estimator for estimating an error rate for said filtered received signal; and
the transmit filter uses feedback from said estimated error rate coupled through a backchannel for tuning said transmit wavelength offset for minimizing said estimated error rate.
4. The system of claim 1 , wherein:
the optical receiver further includes an error estimator for estimating an error rate for said filtered received signal; and
the light generator uses feedback from said estimated error rate coupled through a backchannel for tuning said carrier wavelength for minimizing said estimated error rate.
5. An optical transmission system, comprising:
a filter set having an optical transmit filter and an optical receive filter, wherein a first of the transmit and receive filter has a first wavelength offset with respect to a channel center wavelength defined in a system specification for the system and a second of the transmit and receive filter has a second wavelength offset opposite and equal of said first wavelength offset with respect to said channel center wavelength;
an optical transmitter having said transmit filter for filtering an optical transmit signal; and
an optical receiver for receiving said filtered transmit signal through a link, the receiver including said receive filter for filtering said received signal.
6. A method in an optical transmission system, comprising:
generating an optical transmit signal having a carrier wavelength;
filtering said transmit signal at a transmit wavelength offset with respect to said carrier wavelength;
receiving said filtered transmit signal through a link; and
filtering said received signal at a receive wavelength offset with respect to said carrier wavelength opposite and equal said transmit wavelength offset.
7. The method of claim 6 , further comprising:
estimating an error rate for said filtered received signal; and
tuning said receive wavelength offset according to estimated error rate for minimizing said estimated error rate.
8. The method of claim 6 , further comprising:
estimating an error rate for said filtered received signal;
receiving feedback for said estimated error rate through a backchannel; and
tuning said transmit wavelength offset according to said feedback for minimizing said estimated error rate.
9. The method of claim 6 , further comprising:
estimating an error rate for said filtered received signal;
receiving feedback for said estimated error rate through a backchannel; and
tuning said carrier wavelength according to said feedback for minimizing said estimated error rate.
10. A method in an optical transmission system, comprising:
selecting an optical transmit filter and an optical receive filter as a filter set, wherein a first of the transmit and receive filter has a first wavelength offset with respect to a channel center wavelength defined in a system specification for the system and a second of the transmit and receive filter has a second wavelength offset opposite and equal of said first wavelength offset with respect to said channel center wavelength;
filtering a transmit signal with said transmit filter;
receiving said filtered transmit signal through a link; and
filtering said received signal with said receive filter.
11. An optical transmission system, comprising:
an optical transmitter including a light generator for generating a transmit signal having a carrier center wavelength and an optical transmit filter for filtering said transmit signal at a transmit center wavelength offset with respect to said carrier center wavelength; and
an optical receiver for receiving said filtered transmit signal through a link, the receiver including an optical receive filter for filtering said received signal at a receive center wavelength offset opposite and equal said transmit center wavelength offset with respect to said carrier center wavelength.
12. The system of claim 11 , wherein:
the optical receiver further includes an error estimator for estimating an error rate for said filtered received signal; and
the receive filter uses said estimated error rate for tuning said receive center wavelength offset for minimizing said estimated error rate.
13. The system of claim 11 , wherein:
the optical receiver further includes an error estimator for estimating an error rate for said filtered received signal; and
the transmit filter uses feedback from said estimated error rate coupled through a backchannel for tuning said transmit center wavelength offset for minimizing said estimated error rate.
14. The system of claim 11 , wherein:
the optical receiver further includes an error estimator for estimating an error rate for said filtered received signal; and
the light generator uses feedback from said estimated error rate coupled through a backchannel for tuning said carrier center wavelength for minimizing said estimated error rate.