Polymer Modulator with Passive Waveguide Core
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing polymer ridge waveguide modulators face inefficiencies in optical coupling due to the limited thickness and size of the active region, requiring tight tolerances and increasing costs, and are prone to exposure issues that affect reliability.
Innovation Solution
A polymer modulator design featuring a semiconductor substrate with a passive waveguide core and cladding layers, including sol-gel and SiO2, where the active region is optically coupled to form a continuous passive waveguide core, and a shaped electro-optic polymer active core component with adiabatic transition areas to enhance optical coupling and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the active region layer is used to transverse the complete modulator structure for direct light input and output coupling, then the coupling path is simplified, but the coupling efficiency is reduced and tight tolerances are required
Solution Approach 1:
The patent introduces a passive waveguide core as an intermediary component between the input/output interfaces and the active region. This passive core extends beyond the active region boundaries, allowing light to couple into the waveguide structure before reaching the active modulating section, thereby decoupling the alignment requirements from the active region dimensions and improving coupling efficiency
Solution Approach 2:
The patent extends the passive waveguide core in the longitudinal dimension beyond the active region, creating an overhang structure that protrudes from the sides of the active region. This dimensional extension provides a larger coupling aperture and relaxes alignment tolerances without compromising the compact footprint of the active modulating section
2Volume of moving object
If the active region layer is limited in thickness and size, then the modulator structure remains compact, but direct coupling to optical fibers and free space light becomes inefficient
Solution Approach 1:
The patent resolves the size-efficiency contradiction by extending the passive waveguide core beyond the active region boundaries in the longitudinal dimension. This creates an overhang structure that provides enhanced coupling aperture and mode matching without significantly increasing the overall device footprint, thereby maintaining compactness while improving coupling efficiency
Solution Approach 2:
The patent divides the waveguide structure into distinct passive and active regions, with the passive core serving as a coupling interface that extends beyond the active modulating section. This segmentation allows the coupling region to be optimized independently from the active region, enabling efficient optical coupling while maintaining a compact active section
3Ease of operation
If the active material is exposed to the outside world, then direct optical coupling is achieved, but reliability is reduced due to exposure to atmosphere and optical reflections
Solution Approach 1:
The patent uses the passive waveguide core as a mediator that interfaces with the external optical environment while the active material remains enclosed. The passive core acts as a protective barrier that transmits optical energy to and from the active region without exposing the sensitive active material to atmospheric exposure and optical reflections, thereby maintaining both coupling accessibility and material stability
4Reliability
If the refractive index difference between core and cladding is increased, then light transmission is improved, but fabrication complexity may increase
Solution Approach 1:
The patent optimizes the refractive index parameters by selecting materials with appropriate index differences between the passive core and cladding layers. By carefully controlling these optical parameters within practical ranges, the patent achieves improved light transmission and mode confinement while maintaining compatibility with standard fabrication processes, avoiding excessive fabrication complexity
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 design improves optical coupling efficiency and reliability by confining the active material within the chip, reducing exposure to external factors and minimizing optical reflections, while allowing for more flexible fabrication and higher refractive index differences for better light transmission.
Implementation Method 1
an active region optically coupling the first passive region and the second passive region to form a continuous passive waveguide core between the light input and the light output
Implementation Method 2
The one of sol-gel and SiO2 surrounding the passive waveguide core in both the first passive region and the second passive region has a first refractive index, the one of sol-gel and SiO2 included in the passive waveguide core in both the first passive region and the second passive region has a second refractive index, and the second refractive index is at least 0.01 higher than the first refractive index
Implementation Method 3
a shaped electro-optic polymer active core component with adiabatic transition areas to enhance optical coupling and reliability
Data Source
AI summary
A polymer modulator including a waveguide core defined over an insulating layer and having a first passive region including a light input, a second passive region including a light output, and an active region optically coupling the passive regions into a continuous waveguide core between the input and output. The waveguide core in the first and second passive regions including one of sol-gel and SiO2 surrounded by cladding including one of sol-gel and SiO2. The cladding in the passive regions having a first refractive index, the waveguide core in both regions having a second refractive index at least 0.01 higher than the first refractive index. The waveguide core in the active region including sol-gel, a cladding layer of sol-gel positioned between the insulating layer and the waveguide core, the refractive index of the waveguide core is at least 0.01 higher than the refractive index of the cladding layer.