Distributed traveling-wave Mach-Zehnder modulator driver

Patent metadata

Field	Value
Publication number	US-10320488-B2
Application number	US-201816220203-A
Country	US
Kind code	B2
Filing date	Dec 14, 2018
Priority date	Feb 10, 2014
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

A distributed traveling-wave Mach-Zehnder modulator driver having a plurality of modulation stages that operate cooperatively (in-phase) to provide a signal suitable for use in a 100 Gb/s optical fiber transmitter at power levels that are compatible with conventional semiconductor devices and conventional semiconductor processing is described.

First claim

What is claimed is:

1. A driver amplifier for a distributed traveling-wave modulator comprising a plurality of driver amplifier stages, each driver amplifier stage comprising:
a differential driver amplifier input for receiving a differential input signal from a data source or a previous stage;
a first pair of emitter followers including termination resistors;
a pre-amplifier comprising a differential pair;
a buffer comprising a second pair of emitter followers;
a splitter for splitting the input signal into first and second differential output signals;
a differential driver modulator driver output for receiving the first differential output signal for driving a modulator segment; and
a differential driver signal output for amplifying the second differential output signal for providing the amplified second differential output to a subsequent driver amplifier stage.

2. The driver amplifier according to claim 1 , wherein each driver amplifier stage includes only a single type of transistor to enable high-speed operation.

3. The driver amplifier according to claim 1 , further comprising a plurality of DC bias elements for independently varying biasing voltages of individual driver amplifier stages.

4. The driver amplifier according to claim 3 , wherein each DC bias element is capable of controlling an on state and an off state of a respective driver amplifier stage for shutting down redundant driver amplifier stages.

5. The driver amplifier according to claim 3 , further comprising a delay/relay stage between driver amplifier stages for matching an optical delay between modulator segments, whereby modulations constructively add.

6. The driver amplifier according to claim 5 , wherein a plurality of the DC bias elements are configured to individually control said plurality of delay/relay stages;
wherein each DC bias element is capable of controlling an on state and an off state of a respective delay/relay stage for shutting down redundant delay/relay stages.

7. The driver amplifier according to claim 1 , further comprising a delay/relay stage between driver amplifier stages for matching an optical delay between modulator segments, whereby modulations constructively add.

8. The driver amplifier according to claim 7 , further comprising a plurality of DC bias elements, each DC bias element configured to individually control one of said plurality of delay/relay stages;
wherein each DC bias element is capable of controlling an on state and an off state of a respective delay/relay stage for shutting down redundant delay/relay stages.

9. The driver amplifier according to claim 7 , wherein the plurality of driver amplifier stages comprises four, and the number of delay/relay stages comprises three.

10. The driver amplifier according to claim 1 , wherein each output of each driver amplifier stage is configured to be an open-collector driver for driving modulator segments with different impedances.

11. The driver amplifier according to claim 1 , wherein each output of each driver amplifier stage is configured to be an open-collector cascode driver for driving modulator segments with different impedances.

12. The driver amplifier according to claim 1 , wherein each output of each driver amplifier stage is configured to be an open-collector driver for driving both 25Ω and 50Ω impedance modulator segments.

13. The driver amplifier according to claim 1 , wherein the plurality of driver amplifier stages comprises four.

Assignees

• Elenion Tech Llc

Inventors

• Ding Ran
• Baehr-Jones Thomas Wetteland
• Hochberg Michael J
• Rylyakov Alexander

Classifications

• G02F1/2257

  the optical waveguides being made of semiconducting material · CPC title

• G02F1/025

  in an optical waveguide structure (G02F1/017, {G02F1/2257} take precedence) · CPC title

• G02F1/0123

  Circuits for the control or stabilisation of the bias voltage, e.g. automatic bias control [ABC] feedback loops · CPC title

• G02F2201/127

  travelling wave · CPC title

• H04B10/5561 Primary

  Digital phase modulation · CPC title