Patent ID: 7817922
Filing Date: 2010-10-19
Classification: H04B

Abstract:
1. An apparatus for generating a CS-RZ (carrier suppressed-return to zero) optical signal comprising: a classifier distributing an input signal including a plurality of bits into first and second electrical non-return-to-zero (NRZ) data signals with an identical transmission speed, wherein the first electrical NRZ data signal includes a first plurality of bits of the input signal and the second electric NRZ data signal includes a second plurality of bits of the input signal different from the first plurality of bits; a first signal transformer converting the first NRZ data signal into a first electrical return-to-zero (RZ) data signal using a full-frequency clock; a second signal transformer converting the second NRZ data signal into a second electrical RZ data signal using a full-frequency clock; a phase adjuster tuning a delay time difference between the first and second electrical RZ data signals after the first and second signal transformers have converted the two NRZ signals into the first and second electrical RZ data signals, so that the second electrical RZ data signal has to be delayed against the first electrical RZ data signal by half a period of the first electrical RZ data signal; a bias unit applying different direct current (DC) bias voltages to the first and second RZ electric data signals, respectively; and a dual electrode optical modulator transforming the first electrical RZ data signal and the second electrical RZ data signal delayed against the first electrical RZ data signal into an optical CS-RZ signal; wherein the first and second signal transformers respectively further comprise amplifiers operating in a linear region amplifying the first and second RZ data signals to a driving voltage of a dual electrode optical modulator, and the phase adjuster tunes the delay time difference between the amplified first and second electrical RZ data signals.