OPTICAL MODULATOR, COMMUNICATION SYSTEM, AND COMMUNICATION METHOD

1 . An optical modulator, comprising:

a first branch and a second branch each connectable to an input;

said first branch containing an amplitude modulator and a phase shifter, said amplitude modulator in said first branch being operable by a substantially sinusoidal first signal;

said second branch containing an amplitude modulator that is operable by a second signal that is phase-shifted by substantially 90 degrees relative to the first signal;

a combining unit having two inputs and two outputs and combining the optical fields of said first branch and said second branch;

each of said outputs being arranged to supply an optical carrier.

2 . The optical modulator according to claim 1 , wherein said first and second branches are each connectable to a light source.

3 . The optical modulator according to claim 1 , comprising a two-beam interferometer.

4 . The optical modulator according to claim 1 , wherein said first branch and said second branch each comprises a Mach-Zehnder modulator.

5 . The optical modulator according to claim 2 , wherein a phase of said first branch or a phase of said second branch is adjusted to at least partially compensate a deficient suppression of a frequency of said light source.

6 . The optical modulator according to claim 1 , wherein each output of said combining unit is modulated with an electrical data signal into an optical output signal that is combined and conveyed via an optical fiber.

7 . The optical modulator according to claim 1 , which comprises a splitter connected to said output of said combining unit, a modulator connected to said splitter, and a polarization converter connected to said modulator, said polarization converter outputting a polarized output signal, and wherein the polarized output signal is combined and conveyed via an optical fiber.

8 . The optical modulator according to claim 7 , wherein said optical modulator comprises a third output carrying the signal of the input.

9 . The optical modulator according to claim 1 , configured to supply local oscillator signals in an optical component.

10 . The optical modulator according to claim 9 , configured to supply local oscillator signals in an optical line terminal.

11 . The optical modulator according to claim 9 , wherein each output of the optical modulator is connected to a receiver of the optical component.

12 . A combined optical modulator, comprising a plurality of optical modulators each according to claim 1 , disposed to receive a feed signal from a common light source.

13 . A combined optical modulator, comprising a plurality of optical modulators each according to claim 1 , said plurality of optical modulators including a first optical modulator, a second optical modulator, and a third optical modulator, said first optical modulator having a first output connected to an input of said second optical modulator and a second output connected to an input of said third optical modulator.

14 . A combined optical modulator, comprising:

at least one combined optical modulator comprising a plurality of optical modulators each according to claim 1 , disposed to receive a feed signal from a common light source; and

at least one combined optical modulator comprising a plurality of optical modulators each according to claim 1 , said plurality of optical modulators including a first optical modulator, a second optical modulator, and a third optical modulator, said first optical modulator having a first output connected to an input of said second optical modulator and a second output connected to an input of said third optical modulator.

15 . A communication system, comprising at least one optical modulator according to claim 1 .

16 . A communication system, comprising at least one combined optical modulator formed of a plurality of optical modulators each according to claim 1 and disposed to receive a feed signal from a common light source.

17 . A communication system, comprising at least one combined optical modulator formed of a plurality of optical modulators each according to claim 1 and disposed to receive a feed signal from a common light source, and at least one combined optical modulator formed of a plurality of optical modulators each according to claim 1 and including first, second, and third optical modulators, said first optical modulator having a first output connected to an input of said second optical modulator and a second output connected to an input of said third optical modulator.

18 . A method for providing a plurality of optical carriers based on an input signal, the method which comprises:

feeding an input signal by a splitter to a first branch and to a second branch;

modulating and phase-shifting the input signal by the first branch, thereby amplitude-modulating the input signal by a first, substantially sinusoidal signal;

amplitude-modulating the input signal by a second signal in the second branch, wherein the second signal is phase-shifted by substantially 90 degrees relative to the first signal;

combining the optical fields of the first branch and the second branch by a combining unit, wherein the combining unit supplies two outputs; and

wherein each of the outputs provides an optical carrier.

19 . The method according to claim 18 , which comprises modulating each output of the combining unit with an electrical signal.

20 . The method according to claim 18 , which comprises modulating each output of the combining unit with an electrical signal to form a modulated signal, and feeding the modulated signal via a combiner onto an optical fiber.