Off-Center Groove Integrated Optical Circuit Spurious Light
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrated optical circuits face challenges in reducing the transmission of non-guided spurious light through the substrate, which affects the polarization rejection rate and overall optical quality, particularly in lithium-niobate proton-exchange polarizers and other optical components.
Innovation Solution
An integrated optical circuit design featuring an off-center groove, offset from the median plane, with specific height and width parameters to attenuate non-guided optical beams, replacing the conventional central groove to minimize spurious light transmission and improve polarization rejection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a central groove is used to attenuate non-guided optical beams, then spurious light transmission is reduced, but specular reflections and diffraction patterns from the groove bottom continue to affect optical quality
Solution Approach 1:
The patent applies asymmetry by positioning the groove at an offset from the central median plane of the substrate. This asymmetric placement prevents the groove bottom from generating specular reflections that would otherwise travel directly along the waveguide axis, thereby reducing harmful optical effects while maintaining attenuation of non-guided beams.
Solution Approach 2:
The groove is positioned locally at a specific offset distance from the median plane rather than being centrally symmetric. This local positioning strategy targets the specific path of spurious light while preserving the overall symmetry and functionality of the substrate structure.
2Manufacturing precision
If a central groove is implemented to reduce non-guided light, then polarization rejection rate improves, but the groove structure itself creates diffraction and reflection artifacts
Solution Approach 1:
By introducing asymmetric positioning of the groove relative to the substrate's median plane, the patent eliminates the symmetric specular reflection path that would otherwise create harmful diffraction and reflection artifacts. The asymmetric position ensures that reflected light does not reconstruct the original beam path.
3Object-affected harmful factors
If the groove is positioned centrally to maximize attenuation, then spurious light is most effectively reduced, but specular reflections from the groove bottom travel along the waveguide axis
Solution Approach 1:
The patent deliberately positions the groove asymmetrically away from the central median plane. This asymmetric positioning is specifically designed to prevent the groove bottom from generating specular reflections that would travel along the waveguide axis, while still maintaining effective attenuation of non-guided spurious light.
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 off-center groove design significantly reduces the transmission of spurious light, enhancing the polarization rejection rate and optical quality by offsetting specular reflections and diffraction patterns, thereby improving the performance of integrated optical circuits like polarizers.
Implementation Method 1
at least one groove off-centered with respect to the median plane, said at least one groove extending from the lower face to the inside of the substrate... said at least one groove being capable of attenuating said non-guided optical beam transmitted by the substrate
Implementation Method 2
offsetting specular reflections and diffraction patterns
Implementation Method 3
the effect of optical guiding is linked to a difference of refraction index between the optical waveguide and the substrate
Data Source
AI summary
An integrated optical circuit includes a substrate having an input face, an output face, a lower face and an upper face, an optical waveguide extending between a first end located on the input face of the substrate and a second waveguide end located on the output face of the substrate. The integrated optical circuit further includes at least one off-center groove, the off-center groove extending from the lower face to the inside of the substrate, the at least one off-center groove being located at a non-zero distance d from the median plane, the off-center groove replacing a central groove and the at least one off-center groove being capable of attenuating the non-guided optical beam transmitted by the substrate between the first end and the second end.