Distributed traveling-wave mach-zehnder modulator driver

1. A distributed traveling wave modulator, comprising:

a differential optical input for receiving an optical input carrier signal and a differential optical output for providing a modulated optical carrier signal;

a plurality N of optical phase-shifters connected in series connection as N sequential modulators between said differential optical input and said differential optical output, where N is an integer equal to or greater than 2;

a plurality N of driver amplifier stages, each having a respective differential driver amplifier input and a differential driver amplifier output;

N−1 delay/relay stages, each having a respective differential delay/relay input and a differential delay/relay output;

a first of said plurality N of driver amplifier stages having its input connected to a differential electrical data input;

each of the first N−1 of said plurality N of driver amplifier stages having its output connected to a respective input of a successive one of said N−1 delay/relay stages;

each of said N−1 delay/relay stages having its respective differential delay/relay output connected to the differential driver amplifier input of one of the last N−1 of said plurality N of driver amplifier stages; and

each of said plurality N of driver amplifier stages having a differential signal output connected to a respective one of said N sequential modulators;

wherein each driver amplifier stage includes only a single type of transistor to enable high-speed operation.

2. The distributed traveling wave modulator of claim 1 , wherein N=4.

3. The distributed traveling wave modulator of claim 1 , wherein said N sequential modulators are N sequential Mach-Zehnder modulator pairs.

4. The distributed traveling wave modulator of claim 1 , wherein said distributed traveling wave modulator is an integrated structure supported on a substrate.

5. The distributed traveling wave modulator of claim 4 , wherein said substrate comprises a semiconductor.

6. The distributed traveling wave modulator of claim 5 , wherein said semiconductor comprises silicon.

7. The distributed traveling wave modulator of claim 1 , further comprising a plurality of DC bias elements, each DC bias element configured to control an on state and an off state of a respective one of said plurality N of driver amplifier stages.

8. The distributed traveling wave modulator of claim 1 , wherein said distributed traveling wave modulator is configured to be fabricated using CMOS/BiCMOS technology.

9. The distributed traveling wave modulator of claim 1 , wherein each driver amplifier stage outputs the differential driver amplifier output with a 13 ps delay from the differential driver amplifier input.

10. The distributed traveling wave modulator of claim 1 , wherein each of the plurality N of sequential optical phase shifters comprises a fixed optical length.

11. A method of modulating an optical signal, comprising the steps of:

receiving the optical signal to be modulated at an optical input port;

applying a plurality N of sequential optical phase shifts to said optical signal by operation of a plurality N of fixed-length optical phase-shifters connected in series connection as N sequential modulators, where N is greater than or equal to 2,

each of said N−1 phase shifts after the first of said N phase shifts delayed by a time calculated to apply each of said N−1 phase shifts after the first of said N phase shifts at a respective time when said optical signal is passes a respective one of said N sequential modulators after the first modulator, and

providing a modulated optical signal at an optical output port.

12. The method of modulating an optical signal of claim 11 , wherein N=4.

13. The method of modulating an optical signal of claim 11 , wherein said method of modulating an optical signal is performed in an integrated structure supported on a substrate.

14. The method of modulating an optical signal of claim 13 , wherein said substrate comprises a semiconductor.

15. The method of modulating an optical signal of claim 14 , wherein said semiconductor comprises silicon.

16. The method of modulating an optical signal of claim 11 , wherein said plurality N of optical phase-shifters connected in series connection as N sequential modulators are N sequential Mach-Zehnder modulator pairs.

17. The method of modulating an optical signal of claim 11 , wherein each modulator includes a driver amplifier stage, which includes only a single type of transistor to enable high-speed operation.

18. The method of modulating an optical signal of claim 17 , wherein each driver amplifier stage receives a differential input signal and outputs a differential output signal with a 13 ps delay.