Optical Modulator Generating Multiple Carriers from Single Source
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Solution Overview
Problem
Conventional optical communication systems, such as passive optical networks, face inefficiencies due to the need for electronic processing and high costs associated with providing and modulating multiple optical wavelengths for high data rate applications like Next Generation Optical Access systems, which require precise and numerous laser sources.
Innovation Solution
An optical modulator comprising two branches with amplitude modulators and phase shifters, capable of generating multiple optical carriers with frequency offsets from a single light source, allowing flexible adjustment and reduction in electronic complexity, and optionally using Mach-Zehnder modulators or two-beam interferometers for efficient modulation and polarization multiplexing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple discrete lasers are used to provide individual optical wavelengths, then the required number of wavelengths is provided, but the system complexity and cost increase significantly
Solution Approach 1:
The patent combines multiple optical carrier generation functions into a single integrated optical modulator device. Instead of using separate discrete lasers for each wavelength, the invention uses one optical modulator with multiple outputs to generate multiple optical carriers from a single input optical carrier, thereby reducing the number of laser sources while maintaining the required number of wavelengths.
Solution Approach 2:
The optical modulator is designed to perform multiple functions simultaneously: it generates multiple optical carriers with different frequency offsets, provides polarization multiplexing capability, and enables independent modulation of each output. This multi-functional design eliminates the need for separate laser sources for each wavelength while maintaining system flexibility.
2Quantity of substance
If multiple discrete lasers are used to provide individual optical wavelengths, then the required number of wavelengths is provided, but the precision requirements and costs increase
Solution Approach 1:
The patent combines multiple optical carrier generation functions into a single integrated optical modulator device. Instead of using separate discrete lasers for each wavelength, the invention uses one optical modulator with multiple outputs to generate multiple optical carriers from a single input optical carrier, thereby reducing the number of laser sources while maintaining the required number of wavelengths.
3Productivity
If electronics are used to modulate multiple wavelengths for high data rates, then high data rate transmission is achieved, but the electronic complexity and bandwidth requirements increase
Solution Approach 1:
The patent replaces electronic modulation systems with optical domain processing. Instead of using complex electronic modulators to modulate multiple wavelengths, the invention performs modulation directly in the optical domain using the generated optical carriers, thereby reducing electronic bandwidth requirements and simplifying the electronic complexity while maintaining high data rate transmission capability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables efficient generation and modulation of multiple optical carriers with reduced electronic complexity and cost, supporting high data rate applications like 100 Gbit/s transmission with lower bandwidth requirements for electrical circuitry, and is scalable for various wavelength spacings.
Implementation Method 1
The amplitude modulator modulates the electromagnetic field of the optical signal proportional to the control signal
Implementation Method 2
the phase shifter provides a phase switching of 180-degree at the zero-crossing of the optical signal
Implementation Method 3
a combining unit with two inputs and two outputs that combines the optical fields of the first branch and the second branch
Data Source
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AI summary
An optical modulator is suggested comprising a first branch and a second branch, both being connectable to an input, in particular to a light source; wherein the first branch comprises an amplitude modulator and a phase shifter, wherein the amplitude modulator is operable by a first signal that is substantially sinusoidal; wherein the second branch comprises an amplitude modulator that is operable by a second signal that is substantially 90 degree phase shifted to the first signal; comprising a combining unit with two inputs and two outputs that combines the optical fields of the first branch and the second branch, wherein each output is arranged to supply an optical carrier. Also, a combined optical modulator comprising at least one such optical modulator is provided. Further, a method for providing optical carriers based on an input signal is suggested.