Single Electrode Modulating Multiple Phase Waveguides
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Solution Overview
Problem
Existing high-power laser systems require multiple separate electro-optic phase modulators for each optical channel, leading to inefficiencies in size, weight, power consumption, and scalability, as well as challenges in achieving uniform modulation across channels.
Innovation Solution
A single electrode structure is used to modulate multiple optical channels with similar or different modulation strengths, reducing the need for separate RF drivers and enabling efficient electro-optic phase modulation through optimized electrode and substrate designs in materials like Lithium Niobate, allowing for uniform electric field distribution across multiple waveguides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If separate electro-optic phase modulators are used for each optical channel, then each channel can be individually modulated, but the system size, weight, and power consumption increase significantly
Solution Approach 1:
The patent merges multiple separate electro-optic phase modulators into a single integrated device that simultaneously modulates multiple optical channels. The electrode structure is designed to generate electric fields that uniformly modulate N waveguides, reducing the system from N separate modulators to one shared modulator, thereby significantly reducing weight, size, and power consumption while maintaining individual channel modulation capability
Solution Approach 2:
The single electrode structure serves multiple functions by simultaneously modulating N different optical channels with the same waveform. This universal modulator replaces N dedicated modulators, making the system more compact and efficient while preserving the ability to independently control each channel's modulation through the shared electric field distribution
2Ease of operation
If separate RF drivers and electro-optic phase modulators are used for each optical channel, then each channel receives dedicated drive signal, but the power consumption of RF drive electronics increases N-fold
Solution Approach 1:
The patent combines N separate RF drive signals into a single RF driver that generates one electric waveform. This single waveform is applied to a unified electrode structure that distributes the modulation across N optical channels through its geometric design, reducing power consumption from N separate RF amplifiers to one shared amplifier while maintaining dedicated control over each channel's modulation depth
Solution Approach 2:
The single RF driver and electrode structure serve all N optical channels simultaneously, replacing N dedicated RF drive circuits. The electrode geometry is engineered to ensure uniform electric field distribution across all waveguides, allowing one drive signal to control multiple channels with similar modulation strength, thereby dramatically reducing the power consumption of the RF drive electronics
3Weight of stationary object
If a single electrode structure modulates multiple waveguides, then the size and power consumption of electronic driver circuits are reduced, but achieving uniform modulation across all channels becomes difficult
Solution Approach 1:
The electrode structure is designed with specific geometric characteristics that create locally optimized electric field distributions. By carefully controlling the electrode geometry and positioning, the patent ensures that each waveguide experiences a uniform electric field strength, achieving uniform modulation across all N channels while maintaining a compact single-electrode structure
Solution Approach 2:
The electrode structure is engineered to create equipotential regions that uniformly distribute the electric field across multiple waveguides. This equipotential design ensures that all optical channels experience the same modulation strength, solving the uniformity problem while maintaining the benefits of a single electrode structure with reduced driver circuit complexity
4Adaptability or versatility
If multiple separate phase modulators are used, then each optical channel can be modulated independently, but the system becomes less scalable beyond two waveguides
Solution Approach 1:
The patent creates a universal modulator that can simultaneously modulate N optical channels with the same waveform. This single device replaces N separate modulators, making the system highly scalable. The electrode geometry can be designed to accommodate varying numbers of waveguides, allowing the same basic structure to serve 2, 4, 8, or more channels without increasing device complexity
Solution Approach 2:
The patent merges multiple independent modulation functions into a single integrated device. By sharing the electrode structure and drive electronics across all N channels, the system achieves scalability where adding more channels requires only adding waveguides to the existing structure rather than adding separate modulators, thereby maintaining low device complexity while supporting independent channel modulation
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 results in a significant reduction in RF drive electronics size, weight, and power consumption, while achieving uniform modulation across multiple channels, enhancing the scalability and efficiency of high-power laser systems and increasing the Stimulated Brillouin Scattering threshold for improved output power.
Implementation Method 1
An electric field produced by a suitable electrode structure that is patterned on the electro-optic material interacts with light in the optical waveguide and changes the index of refraction. A suitable electric waveform applied to the electrode structure results in optical broadening through electro-optic phase modulation.
Implementation Method 2
Optical linewidth broadening through electro-optic phase modulation can increase the Stimulated Brillouin Scattering (SBS) threshold of silica fiber and thereby increase the available output power of the laser.
Data Source
AI summary
Electro-optic modulation of multiple phase modulator waveguides with a single electrode is made possible by determining places of equal electric field strength. Substrate extensions support edges of a wide hot electrode and ground electrodes equally spaced from the wide hot electrodes. Waveguides are positioned in the extensions separated from the electrodes by buffer layers. A wide microstrip hot electrode on a buffer layer, wider substrate and ground has multiple waveguides in the substrate below the buffer layer. A thinned substrate has a microstrip hot electrode and spaced coplanar grounds with multiple waveguides located on both sides. Decreasing substrate thickness flattens the electric field strength between the electrodes and allows multiple waveguides located between the central hot and outer ground electrodes. Adjacent waveguides with different asymmetric waveguide index portion staged along their length eliminate cross talk.