The present document relates to an optical communication system. In particular, the present document relates to optical communication systems which can be used in conjunction with electrical amplifiers having increased linearity and bandwidth. An optical transmitter configured to generate a modulating signal for modulating an optical carrier signal is described. The optical transmitter (100) comprises a mapping unit (102) configured to generate a sequence of symbols (130) from input data. The symbols of the sequence of symbols (130) correspond to constellation points of a modulation scheme. The sequence of symbols (130) exhibits a spectrum with a center frequency and left and right sidebands at each side of the center frequency, respectively. Furthermore, the optical transmitter (100) comprises a signal processing unit (103, 104, 105) configured to generate a modified sequence of symbols (131) such that the modified sequence of symbols (131) exhibits a modified spectrum with the center frequency and left and right modified sidebands at each side of the center frequency, respectively. The left and right modified sidebands correspond to the left and right sidebands, which have been shifted away from the center frequency, respectively. In addition, the optical transmitter (100) comprises an amplification unit (107) configured to amplify the modified sequence of symbols (131) to yield the modulating signal.

An optical transmission device includes: a drive signal generate unit that generates a drive signal; a modulation unit that modulates an optical signal in accordance with the drive signal; a detect unit that detects a fluctuation of a signal component of the drive signal with respect to an optical signal output by the modulation unit; and a correct unit that corrects a parameter of the drive signal generate unit in accordance with a detect result of the detect unit so that a non-linear characteristic of the modulation unit gets closer to a linear characteristic.