Mach-Zehnder Optical Modulator Electrodes for Phase Consistency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical waveguide devices experience phase shifts in differential modulation signals due to asymmetrical modulation electrode structures, leading to inconsistencies in signal propagation.
Innovation Solution
The optical waveguide device incorporates a capacitance adjustment mechanism, including dummy electrodes and symmetric electrode designs, to adjust phase velocity and match capacitance, thereby stabilizing differential modulation signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If segment electrodes with different shapes (T-shaped and H-shaped) are used to drive the optical waveguide, then the electrode structure can be simplified and easier to manufacture, but the phase velocity of the differential modulation signal becomes inconsistent, causing phase shift
Solution Approach 1:
The patent applies asymmetry by intentionally designing the two modulation electrodes with different shapes (one T-shaped, one H-shaped) to compensate for the inherent asymmetry in the optical waveguide structure. This asymmetric electrode design balances the overall system symmetry, ensuring that the phase velocities of differential modulation signals on both electrodes become consistent, thereby suppressing phase shift while maintaining manufacturing simplicity.
2Ease of operation
If clearances between proximity electrodes are made different to adjust electrode spacing, then the electrode configuration can be optimized for signal propagation, but the phase velocity of the differential modulation signal changes, resulting in phase shift
Solution Approach 1:
The patent applies parameter changes by systematically adjusting the clearance distances between proximity electrodes on different electrodes. By varying these geometric parameters, the patent optimizes the electrode configuration for signal propagation while compensating for phase velocity differences. This parameter optimization ensures consistent phase velocity across both electrodes, suppressing phase shift in the differential modulation signal.
3Volume of moving object
If a thin plate substrate is used to achieve miniaturization and broadband driving signal, then the device size is reduced and bandwidth is increased, but the drive voltage increases, requiring differential modulation to reduce voltage
Solution Approach 1:
The patent applies periodic action by using differential modulation with reverse-phase signals on two electrodes. This periodic signal configuration allows the optical waveguide device to operate at higher bandwidth while maintaining low drive voltage. The differential modulation technique enables the device to achieve miniaturization with thin plate substrate while keeping the effective drive voltage low through the complementary action of the two electrodes.
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
The solution effectively suppresses phase shifts in differential modulation signals, ensuring consistent signal propagation and improving the performance of optical modulation devices and transmission apparatuses.
Implementation Method 1
a capacitance adjustment mechanism for adjusting a phase velocity of the modulation signal propagating through the modulation electrode
Implementation Method 2
an optical waveguide device in which an optical waveguide including at least one Mach-Zehnder type optical waveguide is formed on a substrate, and two branched waveguides configuring the Mach-Zehnder type optical waveguide are each provided with two modulation electrodes for applying a differential modulation signal
Data Source
Figure 1~2
Figure 3
Figure 4A~4C
AI summary
An optical waveguide device in which an optical waveguide including at least one Mach-Zehnder type optical waveguide is formed on a substrate, and two branched waveguides 10 configuring the Mach-Zehnder type optical waveguide are each provided with two modulation electrodes (E1, E2) for applying a differential modulation signal, wherein each of the modulation electrodes includes a plurality of proximity electrodes (PE11 to PE22) disposed in a divided manner along the branched waveguide, a signal electrode (LE1, LE2) for propagating the modulation signal, and a bypass electrode (BE1, BE2) connecting the proximity electrodes and the signal electrode, and a capacitance adjustment mechanism (DE) for adjusting a phase velocity of the modulation signal propagating through the modulation electrode is provided on at least one of the two modulation electrodes (E1, E2).