Direct-Drive Polymer Modulator Waveguide Poling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current 3-layer polymer modulators are not direct-drive modulators, leading to inefficient poling due to voltage division among layers, resulting in dielectric breakdown in the cladding before complete poling can be accomplished in the core, and they have small Vn-L products due to short length and high single-layer r33 coefficients.
Innovation Solution
A direct-drive polymer modulator is developed with a multilayer waveguide structure including a bottom and top electro-optic polymer cladding layer and an electro-optic polymer core, where the core has an electro-optic coefficient (r33) greater than 250 pm/V and a glass transition temperature (Tg) of 150° C. to >200° C., and the cladding layers have a Tg matching the core and higher conductivity than the core, allowing for efficient poling and direct-drive operation without an external driver circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a 3-layer polymer modulator structure is used, then the modulator achieves high performance with multi-GHz operation, but the poling becomes inefficient due to voltage division among the three layers causing dielectric breakdown in the cladding before complete poling in the core
Solution Approach 1:
The patent applies local quality by making the cladding layers conductive specifically at the poling temperature range, while maintaining dielectric properties at operating temperatures. This localized property change allows the cladding to conduct during poling (preventing breakdown) but insulate during operation (maintaining modulation function), thus resolving the voltage division problem without compromising overall device performance
Solution Approach 2:
The patent changes the electrical parameter (conductivity) of the cladding layers as a function of temperature. By selecting materials whose conductivity increases significantly at poling temperatures, the system achieves high poling efficiency while maintaining the necessary dielectric properties at lower operating temperatures, thereby eliminating the voltage division issue
2Ease of operation
If the cladding layers are made conductive to enable direct-drive operation, then the modulator achieves very-low voltage operation without driver circuit, but the conductivity must be carefully controlled to prevent dielectric breakdown during poling
Solution Approach 1:
The patent employs periodic action by applying high voltage only during the brief poling process, then switching to low voltage for normal operation. The conductive cladding enables this periodic regime by allowing high voltage application during poling without sustained breakdown, while maintaining reliability during the extended low-voltage operation period
Solution Approach 2:
The patent applies preliminary action by performing the poling process first to establish the electro-optic properties in the core, then switching to normal operation mode. The conductive cladding facilitates this sequence by enabling the preliminary high-voltage poling step without causing breakdown, thereby preparing the device for subsequent low-voltage direct-drive operation
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 enables efficient poling and direct-drive operation of the polymer modulator, reducing the drive voltage and increasing the electro-optic coefficient, resulting in a high-performance, multi-GHz modulator with negligible light leakage to the substrate, which can be integrated with lasers on a common platform.
Implementation Method 1
an electro-optic polymer core and a top electro-optic polymer cladding layer, the electro-optic polymer core having an electro-optic coefficient (r33) greater than 250 pm/V
Data Source
AI summary
A direct-drive polymer modulator including a platform, a multilayer waveguide formed in/on the platform, the waveguide including a bottom cladding layer, an electro-optic polymer core and a top cladding layer, and at least a portion of the waveguide forming a direct-drive polymer modulator.