Photonic Crystal Laser Element Polarization Stability
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Solution Overview
Problem
Conventional laser elements with photonic crystal layers face issues in maintaining constant polarization directions due to performance degradation, leading to varied laser beam patterns, which existing techniques struggle to address effectively.
Innovation Solution
Incorporating a second finer refractive index region near a first refractive index region with approximate circular, square, or regular polygon shapes in the photonic crystal layer, and adjusting the rotational angle of the second region based on coordinates, allows for the emission of laser beams with various patterns by modulating intensity across different areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional photonic crystal layers with circular different refractive index regions are used, then the structure is simple and easy to manufacture, but the polarization directions are not constant and mode performance degrades
Solution Approach 1:
The patent introduces asymmetric elements by placing a second different refractive index region at a specific position relative to the first different refractive index region. This asymmetric configuration modifies the mode distribution and electric field vector directions, enabling constant polarization directions while maintaining manufacturability through a relatively simple structural modification
Solution Approach 2:
The patent applies local quality by creating regions with different refractive indices (first and second different refractive index regions) at specific locations within the photonic crystal layer. These localized refractive index variations are strategically positioned to control polarization directions and improve mode performance without requiring complete restructuring of the entire layer
2Reliability
If asymmetric different refractive index regions are introduced to fix polarization directions, then polarization stability improves, but the ability to generate various laser beam patterns is limited
Solution Approach 1:
The patent implements dynamics by making the rotational angle of the second different refractive index region variable depending on the coordinates of the first different refractive index region. This dynamic angular configuration allows the system to adapt and generate various laser beam patterns (circular, linear, annular, character shapes) while maintaining constant polarization directions, thus achieving both reliability and versatility
Solution Approach 2:
The patent applies parameter changes by varying the rotational angle parameter of the second different refractive index region based on the positional coordinates. This parameter variation enables control over different laser beam patterns while preserving polarization stability, resolving the contradiction between fixed polarization and pattern diversity
3Adaptability or versatility
If multiple different refractive index regions with varying rotational angles are disposed, then various laser beam patterns can be generated, but the structural complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the photonic crystal layer into multiple unit configurations, each containing a first and second different refractive index region. This modular approach allows systematic control of laser beam patterns through coordinated arrangement of segmented units, managing complexity through organized structure rather than random complexity
Solution Approach 2:
The patent introduces a new dimension by making the rotational angle of the second different refractive index region dependent on the two-dimensional coordinates (X, Y) of the first different refractive index region. This dimensional approach enables pattern control through spatial variation of rotational angles, achieving versatility without proportionally increasing structural complexity
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 enables the production of laser beams with diverse patterns, including single- or multiple-spot, annular, linear, character, and Laguerre-Gaussian shapes, by effectively managing the polarization and intensity distribution through the photonic crystal layer.
Implementation Method 1
a photonic crystal layer on which laser light is incident, wherein the photonic crystal layer includes a base layer formed of a first refractive index medium; and a plurality of different refractive index regions formed of a second refractive index medium having a refractive index different from that of the first refractive index medium
Implementation Method 2
the plurality of different refractive index regions includes a first different refractive index region of which a planar shape is an approximate circle, an approximate square, or an approximate regular polygon having a rotational symmetry of 90°
Data Source
AI summary
A laser element includes a photonic crystal layer on which laser light is incident. The photonic crystal layer includes a base layer formed of a first refractive index medium; and a plurality of different refractive index regions formed of a second refractive index medium having a refractive index different from that of the first refractive index medium and disposed in the base layer. The plurality of different refractive index regions includes a first different refractive index region of which a planar shape is an approximate circle, an approximate square, or an approximate polygon having a rotational symmetry of 90° and a first area perpendicular to a thickness direction; and a second different refractive index region having a second area perpendicular to a thickness direction.