Integrated Semiconductor Device Butt-Joint Waveguide Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional integrated optical devices face challenges in achieving high optical coupling efficiency and reliability due to the use of the same mesa waveguide structure for both laser diodes and optical modulators, leading to degradation in emission properties and reliability.
Innovation Solution
The integrated semiconductor device employs a substrate with distinct waveguide structures for the laser diode and optical modulator, utilizing a ridge waveguide for the laser diode and a stripe-shaped mesa waveguide for the optical modulator, with a butt-joint connection between the core layers to reduce light reflection and enhance reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the same mesa waveguide structure is used for both laser diode and optical modulator, then production is easy and butt-joint connection is easy to establish, but optical coupling efficiency is low and reliability is degraded
Solution Approach 1:
The patent applies local quality by assigning different waveguide structures to different functional regions: the laser diode region uses a ridge waveguide structure optimized for light emission, while the optical modulator region uses a mesa waveguide structure optimized for high-frequency modulation. This localized differentiation allows each component to operate at its optimal performance level while maintaining overall integration on a single substrate.
2Reliability
If different waveguide structures (ridge for laser diode, mesa for optical modulator) are integrated on a single substrate, then reliability and emission properties are improved, but optical coupling efficiency between waveguides is low
Solution Approach 1:
The patent introduces an optical coupling section as an intermediary component between the ridge waveguide of the laser diode and the mesa waveguide of the optical modulator. This coupling section serves as a transition zone that facilitates efficient optical energy transfer between the two different waveguide structures, thereby reducing optical loss while maintaining the benefits of differentiated waveguide designs.
3Speed
If different waveguide structures are used, then high-frequency modulation characteristics are improved, but optical coupling between waveguides becomes difficult
Solution Approach 1:
The patent segments the integrated optical device into distinct functional sections with dedicated waveguide structures: the laser diode section with ridge waveguide for light generation, the optical coupling section for efficient light transfer, and the optical modulator section with mesa waveguide for high-speed modulation. This segmentation allows each section to be optimized independently for its specific function while maintaining overall system integration.
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 configuration improves the reliability and emission properties of the light-emitting portion while ensuring stable and efficient light modulation by minimizing optical loss and maintaining high-frequency modulation characteristics.
Implementation Method 1
The second core layer is joined to the first core layer by a butt-joint method
Data Source
AI summary
An integrated semiconductor device includes a substrate including first, second and third portions; a first waveguide provided on the first portion, the first waveguide including a first base portion containing a first core layer, and a first ridge portion provided on the first base portion; a second waveguide provided on the second portion, the second waveguide including a second base portion containing a second core layer and a second ridge portion provided on the second base portion; and a third waveguide provided on the third portion, the third waveguide including a stripe-shaped mesa containing a third core layer. The second base portion is connected to the first base portion. The second ridge portion is connected to the first ridge portion and the stripe-shaped mesa. The second core layer is formed integrally with the third core layer and is joined to the first core layer by a butt-joint method.