MMI Waveguide Port Layout for Low-Loss Tunable Lasers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wavelength-tunable lasers with ring resonators suffer from high light loss and stray light issues due to processing errors in multi-mode interference waveguides, which affect device performance and yield.
Innovation Solution
The optical device incorporates a 1×2 multi-mode interference waveguide configuration with specific port arrangements to minimize light loss and utilize shared light processing portions to manage stray light effectively, reducing sensitivity to processing errors and enhancing device robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a 2×2 multi-mode interference waveguide is used at the junction of linear and ring waveguides, then the device can achieve wavelength tuning functionality, but light loss increases due to processing errors in the waveguide
Solution Approach 1:
The patent divides the multi-mode interference waveguide into separate functional sections: a 1×2 MMI waveguide for coupling the linear waveguide to the ring resonator, and a 2×2 MMI waveguide for the wavelength tuning function. This segmentation allows each section to be optimized independently, reducing the impact of processing errors on overall light loss while maintaining wavelength tuning capability.
2Measurement precision
If a 2×2 multi-mode interference waveguide is used for wavelength tuning, then wavelength selectivity is achieved, but stray light is generated that affects device performance
Solution Approach 1:
The patent extracts and separates the stray light paths from the main optical path by using distinct port arrangements. The 1×2 MMI waveguide configuration with specifically positioned ports allows stray light generated during wavelength tuning to be directed to dedicated output ports rather than contaminating the main signal path, thereby maintaining wavelength selectivity while eliminating harmful stray light effects.
3Ease of manufacture
If standard port arrangements are used in the multi-mode interference waveguide, then manufacturing is simplified, but light loss increases due to sensitivity to processing errors
Solution Approach 1:
The patent employs asymmetric port arrangements in the 1×2 MMI waveguide section, where ports are positioned at non-symmetric locations relative to the waveguide center. This asymmetric configuration reduces the sensitivity to processing errors and misalignments during manufacturing, thereby reducing light loss while still allowing for relatively simple fabrication processes.
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 significantly reduces light loss and improves the yield of wavelength-tunable lasers by minimizing processing errors and effectively managing stray light, leading to enhanced performance and tolerance.
Implementation Method 1
a multi-mode interference waveguide that includes a first end portion in a first direction, and a second end portion in opposite direction to the first direction; a first port that is arranged in the first end portion and that is placed away, in a second direction intersecting with the first direction, from a center of the first end portion in the second direction; a second port that is arranged in the first end portion and that is positioned on an opposite side of the first port with respect to the center of the first end portion in the second direction; a third port that is arranged in the second end portion and that is positioned at a center of the second end portion in the second direction; and two fourth ports that are arranged in the second end portion and that are positioned on both sides of the third port in the second direction, the multi-mode interference waveguide being configured such that same-phase components of lights input to the first port and the second port are coupled at the third port, and antiphase components of lights input to the first port and the second port are coupled at the two fourth ports
Data Source
AI summary
An optical device includes: a multi-mode interference waveguide that includes a first end portion in a first direction and a second end portion in opposite direction to the first direction; a first port that is arranged in the first end portion; a second port that is arranged in the first end portion; a third port that is arranged in the second end portion and that is positioned at a center of the second end portion in the second direction; and two fourth ports that are arranged in the second end portion and that are positioned on both sides of the third port in the second direction.