Modulating Interferometer Phase Shift Control for Optical Power
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing high-speed optical communication systems face limitations in achieving advanced modulation formats like higher-order QAM formats due to complex drive electronics and low transmission power, particularly when using two-armed structures and multiple electrode segments, which are costly and less suitable for high-frequency applications.
Innovation Solution
A method for modulating a carrier light wave using a modulating interferometer with four parallel-coupled waveguiding paths, where each symbol is phase shifted by a combination of static and variable phase shifts, ensuring equal absolute values for specific phase shift amounts, allowing for higher transmission power without complex drive electronics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple electrode segments are used to control phase shifts in each optical path, then modulation precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent divides the optical modulator into multiple independent electrode segments along each optical path, where each segment can be controlled independently to achieve precise phase modulation. This segmentation allows fine-grained control of the refractive index distribution, enabling accurate representation of complex modulation formats like 16-QAM and 64-QAM while maintaining manageable system complexity through modular design
Solution Approach 2:
Different electrode segments are assigned different control voltages to create localized phase shifts in specific regions of the optical paths. This local quality approach allows independent optimization of phase modulation in each segment, enabling precise control over the overall modulation pattern without requiring uniform control throughout the entire device
2Device complexity
If two-armed Mach-Zehnder modulator structure is used, then device complexity is reduced, but transmission power decreases
Solution Approach 1:
The patent extends the traditional two-armed Mach-Zehnder structure by adding more optical paths (four or more arms) to create a multi-dimensional interference pattern. This dimensional expansion allows the system to maintain simpler electrode control while achieving higher transmission power through constructive interference across multiple paths simultaneously, resolving the trade-off between device complexity and power transmission
3Productivity
If higher-order QAM formats are implemented using conventional methods, then information capacity is improved, but drive electronics complexity increases
Solution Approach 1:
The patent designs a universal modulator structure with multiple electrode segments that can be configured to support various modulation formats (BPSK, QPSK, 16-QAM, 64-QAM) by simply changing the control voltage patterns. This multi-functional design eliminates the need for separate drive electronics for each modulation format, as the same physical structure with adjusted electrical control can achieve any desired modulation scheme
Solution Approach 2:
The system achieves different modulation formats by changing the parameter values (control voltages) applied to the electrode segments rather than changing the physical structure. This parameter-based approach allows flexible adaptation to different information capacities and modulation requirements while maintaining identical hardware, significantly reducing drive electronics complexity
4Length of moving object
If output light power is increased to compensate for low transmission power, then transmission distance is improved, but energy consumption increases
Solution Approach 1:
The patent converts the normally destructive interference effect in Mach-Zehnder modulators into a beneficial constructive interference effect by carefully designing the phase shifts in multiple optical paths. This transformation allows the system to achieve high transmission power and long transmission distance without requiring additional energy input, as the interference pattern itself amplifies the signal rather than consuming energy to overcome losses
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 approach enhances transmission power, reduces the need for amplifiers, and simplifies electronics, making it more suitable for high-frequency applications while maintaining high signal quality.
Implementation Method 1
it is known to split the carrier light wave using a splitter, and to recombine the carrier light wave in a combiner after a relative phase shift of the different light paths between the splitter and combiner. The phase shift can for instance be achieved using electrodes attached to each path, to each of electrodes a variable electric signal can be applied so that the refractive index of the path wave guide material changes
Implementation Method 2
it is known to split the carrier light wave using a splitter, and to recombine the carrier light wave in a combiner after a relative phase shift of the different light paths between the splitter and combiner
Data Source
AI summary
Method for modulating a carrier light wave with symbols, led through a modulating interferometer, the total path phase shift being the sum of a respective first, second, third or fourth static phase shift and a respective first, second, third or fourth variable modulating phase shift amount. For each of at least two symbols:the first variable modulating phase shift equals the sum of the first pair phase shift and the common phase shift;the second variable modulating phase shift equals the sum of the negative of the first pair phase shift and the common phase shift;the third variable modulating phase shift equals the sum of the second pair phase shift and the negative of the common phase shift;the fourth variable modulating phase shift equals the sum of the negative of the second pair phase shift and the negative of the common phase shift.