Bent Waveguide Core With Continuous Curvature for Lower Mode Loss
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Solution Overview
Problem
Conventional bent waveguide cores experience mode transition loss due to shifts in optical mode centers caused by varying curvatures, particularly at connections between straight and bent segments, necessitating improved designs to reduce loss and enhance energy efficiency.
Innovation Solution
A waveguide core with smooth curves having continuous curvature and its first-order derivative, allowing seamless transitions between segments of different curvatures, optionally incorporating thermo-optic phase shifters for enhanced energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a waveguide core uses conventional bent segments with discrete curvature changes, then the structure is simpler to manufacture, but mode transition loss increases at connection points between segments of different curvatures
Solution Approach 1:
The patent applies continuous curvature transitions in the waveguide path, replacing discrete angular bends with smooth curved segments. The curvature κ(s) is defined as a continuous function of arc length s, ensuring that the waveguide transitions gradually between different curvature states rather than making abrupt angular changes. This continuous curvature approach minimizes mode transition loss by maintaining adiabatic conditions during bending transitions.
Solution Approach 2:
The patent introduces dynamic curvature variation along the waveguide path, where the curvature κ(s) changes continuously according to a defined function rather than remaining constant or changing abruptly. This dynamic approach allows the waveguide to adapt its bending characteristics along its length, optimizing the transition between straight and bent segments while minimizing energy loss.
2Loss of energy
If the waveguide core has abrupt curvature changes at segment connections, then the manufacturing process is simpler, but the optical performance deteriorates due to increased mode transition loss
Solution Approach 1:
The patent defines the waveguide path using continuous curvature functions κ(s) that smoothly transition between different bending states. This mathematical approach ensures that the curvature and its derivatives are continuous throughout the waveguide, eliminating abrupt changes that would cause mode transition loss while providing precise control over the geometric profile for manufacturing.
Solution Approach 2:
The patent employs parameterized curvature functions where the curvature κ is expressed as a continuous function of arc length s. By controlling the parameters of these functions (such as bending radius, transition length, and curvature distribution), the patent achieves precise curvature transitions that minimize optical loss while maintaining manufacturability through defined geometric parameters.
3Loss of energy
If conventional Euler curves are used for bending transitions, then some mode transition loss is reduced, but further loss reduction and energy efficiency improvement are still needed
Solution Approach 1:
The patent extends beyond static Euler curve approximations by implementing dynamic curvature functions κ(s) that are explicitly defined as continuous functions of arc length. This allows for optimized curvature distributions that adapt to the specific geometric requirements of each waveguide segment, achieving lower mode transition loss and improved energy efficiency compared to conventional fixed-curvature approaches.
Solution Approach 2:
The patent utilizes parameterized curvature functions with adjustable parameters that can be optimized for different waveguide configurations. By varying these parameters (such as transition length, curvature magnitude, and distribution profile), the patent achieves superior loss reduction and energy efficiency compared to conventional Euler curves, while maintaining design flexibility for various applications.
Data Source
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AI summary
The disclosure relates to waveguides. The disclosure proposes a waveguide core (100), wherein the waveguide core (100) is bent according to a certain curve (101) or family of curves. The waveguide core (100) has a smooth curve (101) as an edge and/or centerline of the waveguide core (100), wherein a curvature of the smooth curve (101) is continuous and the first order derivative of the curvature of the smooth curve (101) with respect to an arc length of the smooth curve (101) is continuous. The smooth curve (101) comprises a curve start point (102) and a curve end point (103), wherein the derivative of the curvature of the smooth curve (101) is zero at the curve start point (102) and at the curve end point (103); and wherein the curvature of the smooth curve (101) is zero at the curve start point (102), and is non-zero or zero at the curve end point (103).