Partially Transparent Reflector Structure for LIDAR Heat Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional metallic micro-mirrors in LIDAR devices experience significant heating due to high light absorption, leading to thermomechanical damage, while Bragg reflector stacks, although less absorbent, face issues with mechanical deformation and complex manufacturing.
Innovation Solution
A partially transparent mirror with integrated diffusion and/or absorption means, such as metallic layers, carbon nanotubes, heat sinks, or Bragg stacks, coupled with heat dissipation mechanisms, limits light absorption and dissipates heat effectively, preventing temperature rise and mechanical deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a metallic reflective layer is used to achieve high reflectivity, then the reflection coefficient is improved (96-98%), but the absorption coefficient increases (2-4%), causing significant heating and thermomechanical damage
Solution Approach 1:
The reflector device is segmented into multiple functional layers: a partially transparent mirror (first reflector) and separate diffusion/absorption means positioned behind it. This segmentation allows the mirror to handle reflection while dedicated means handle heat management, resolving the contradiction between high reflectivity and heat generation.
Solution Approach 2:
Diffusion and absorption means act as intermediary elements between the incident radiation and the mirror substrate. These intermediary means diffuse and absorb transmitted radiation, preventing direct heating of the mirror while maintaining high reflection coefficients.
2Temperature
If a Bragg reflector stack is used to reduce light absorption and heating, then the absorption coefficient is reduced, but the number of elementary reflector stacks must be large, leading to mechanical stresses and deformations
Solution Approach 1:
The invention extracts the heat management function from the reflective function. Instead of using a complex Bragg stack to simultaneously achieve reflection and heat management, the invention separates these functions: a simple partially transparent mirror for reflection and separate diffusion/absorption means for heat management, eliminating mechanical stresses from excessive layering.
Solution Approach 2:
The reflector device uses a composite structure combining a partially transparent mirror with diffusion and/or absorption means. This composite approach achieves both high reflectivity and effective heat management without the mechanical deformation issues of complex Bragg stacks.
3Illumination intensity
If the number of elementary Bragg reflector stacks is increased to maximize reflection coefficient, then the reflection performance is improved, but the manufacturing complexity and mechanical stress increase
Solution Approach 1:
The device segments reflection and heat management into separate components, allowing each to be optimized independently. The partially transparent mirror provides reflection while the separate diffusion/absorption means handle thermal management, simplifying manufacturing compared to complex multi-layer Bragg stacks.
Solution Approach 2:
The composite structure of a partially transparent mirror combined with diffusion and/or absorption means achieves high reflection coefficients without requiring numerous sequential layers, thereby reducing manufacturing complexity while maintaining optical performance.
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 enables operation at higher incident radiation powers with increased laser damage thresholds and prevents performance degradation by minimizing heat buildup and mechanical stress on the mirror.
Implementation Method 1
a partially transparent mirror (23), and having a partially reflective front face (24)
Implementation Method 2
means for diffusing and/or absorbing light radiation configured to diffuse and/or absorb, directly, light radiation that may be transmitted through a rear face
Implementation Method 3
an absorption layer, advantageously the absorption layer being for example a metallic layer, or a layer formed of carbon nanotubes
Implementation Method 4
or a heat sink comprising a bulk material for example carbon, metal and structured or unstructured to dissipate heat
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a reflector device (10) intended to reflect light radiation of wavelength λ, the device is provided with a support on which are assembled: - a partially transparent mirror (23), and having a partially reflective front face (24); - means for diffusing and/or absorbing light radiation (26) configured to diffuse and/or absorb light radiation that may be transmitted by a rear face (25), opposite to the front face (24).