Offset-Strip Phase Shifter Structure for High Optical Power
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional phase shifters on photonic chips are limited by their ability to tolerate high optical powers.
Innovation Solution
A phase shifter structure comprising a first and second section with a laterally offset strip and waveguide core, surrounded by dielectric layers and slab layers, which enhances thermo-optic and electro-optic responses while minimizing nonlinear absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional phase shifter structures are used, then phase modulation can be achieved, but the ability to tolerate high optical powers is limited
Solution Approach 1:
The phase shifter is divided into multiple sections (first section, second section) with a strip structure laterally offset from the waveguide core. This segmentation allows the optical mode to be distributed across different regions, reducing peak intensity and minimizing nonlinear absorption effects while maintaining phase modulation capability through cumulative phase shift across sections.
Solution Approach 2:
The structure employs different materials with specific properties in different locations: silicon or semiconductor material for the phase shifter sections and strip, silicon nitride or dielectric material for the waveguide core, and dielectric layers for insulation. This local material optimization enables regions to be tailored for either high optical power tolerance or effective phase modulation.
2Adaptability or versatility
If the strip is positioned closer to one section, then asymmetric phase control is achieved, but manufacturing precision requirements increase
Solution Approach 1:
The strip is deliberately positioned with a lateral offset toward one of the phase shifter sections, creating an asymmetric structure. This asymmetry enables differential phase control between the two arms of the Mach-Zehnder interferometer, allowing for efficient phase tuning. The offset distance can be optimized to achieve the desired phase modulation range while remaining within manufacturing tolerances.
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 structure improves power handling capability and phase tuning efficiency by leveraging thermo-optic and electro-optic mechanisms, allowing for effective phase modulation of light with reduced nonlinear absorption.
Implementation Method 1
One type of phase shifter may operate by a thermo-optic mechanism in which heat is transferred to the waveguide core, which has a refractive index that varies with temperature.
Implementation Method 2
Another type of phase shifter may operate by an electro-optic mechanism in which a p-n junction inside the waveguide core is biased.
Data Source
Figure 1~1A
Figure 2~2A
Figure 3~4
AI summary
Structures for a phase shifter and methods of forming such structures. The structure comprises a phase shifter including a first section, a second section, and a strip laterally between the first section and the second section. The structure further comprises a waveguide core including a portion laterally between the first section and the second section of the phase shifter, and a dielectric layer between the waveguide core and the phase shifter. The strip is laterally offset relative to the portion of the waveguide core toward the first section of the phase shifter.