Patent ID: 11953800
Assignee: NOKIA SOLUTIONS AND NETWORKS OY
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 11:
12. The apparatus according to claim 11, further comprising:
a third optical modulator and a fourth optical modulator connected in parallel with the first optical modulator and the second optical modulator for outputting a third modulated output signal and a fourth modulated output signal, respectively;
a second combiner for combining the third modulated output signal and the fourth modulated output signal;
a second additional phase shifter between the fourth optical modulator and the second combiner to provide a second phase shift between the third modulated output signal and the fourth modulated output signal;
a polarization rotator for rotating the polarization of the third modulated output signal and the fourth modulated output signal; and
a polarization combiner for combining the first modulated output signal, the second modulated output signal, the third modulated output signal, and the fourth modulated output signal.