Aspherical Optical Window for LiDAR Reflectivity Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Laser radar apparatuses face challenges in uniformly canceling reflected light due to varying reflectivity of optical windows, which affects sensitivity and noise reception, particularly due to the high sensitivity of light-receiving elements and the dependence on irradiation direction.
Innovation Solution
The optical window is designed with an aspherical shape to maintain reflectivity below a certain upper limit across a specified range, using linearly polarized light and without the need for mechanical adjustments, by optimizing the angle of incidence and polarization direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a flat optical window is used, then the apparatus structure is simple, but the reflectivity varies significantly with irradiation angle causing non-uniform detection sensitivity
Solution Approach 1:
The optical window is designed with an aspherical curved surface instead of a flat surface. The curvature is specifically optimized so that light beams irradiated at different angles within the preset wide angle range all incident on the optical window at angles that maintain reflectivity below a predetermined threshold, thereby achieving uniform detection sensitivity across the irradiation range.
2Measurement precision
If the optical window reflectivity is reduced for all angles, then detection sensitivity is improved, but the apparatus requires complex mechanical adjustments or polarizing means
Solution Approach 1:
The aspherical shape of the optical window inherently controls the angle of incidence for all irradiation directions, eliminating the need for mechanical adjustments or complex polarizing means. The curved surface geometry is designed to maintain low reflectivity across the entire preset wide angle range without requiring any moving parts or additional optical components.
Solution Approach 2:
The patent changes the geometric parameter of the optical window from flat to aspherical, which fundamentally alters how light interacts with the surface. This parameter change enables the optical window to maintain low reflectivity for all irradiation angles within the preset range, improving detection sensitivity without adding mechanical complexity.
3Area of stationary object
If the irradiation angle range is widened, then the coverage area is increased, but the reflectivity control becomes more difficult and detection uniformity deteriorates
Solution Approach 1:
The aspherical optical window is specifically designed to handle wide-angle irradiation. The curved surface geometry ensures that even light beams at extreme angles within the preset wide angle range incident on the optical window at controlled angles, maintaining low reflectivity and uniform detection sensitivity across the entire expanded coverage area.
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 effectively suppresses reflectivity within the specified range, simplifying the apparatus and improving detection accuracy by maintaining low reflectivity for both S- and P-polarized light, thereby reducing noise and enhancing sensitivity uniformly across the irradiation range.
Implementation Method 1
the reflectivity of the optical window varies depending on the angle of incidence of the light
Implementation Method 2
The light source is configured to emit irradiation light with linear polarization
Data Source
AI summary
A light irradiation apparatus includes an optical window, a light source and an irradiation unit. The optical window is formed of a light-transmissive material. The light source is configured to emit irradiation light with linear polarization. The irradiation unit is configured to irradiate the irradiation light emitted from the light source toward a preset irradiation range through the optical window. Moreover, the optical window has a shape such that the reflectivity of the irradiation light within a specified range is lower than or equal to a preset upper limit; the specified range is provided within the irradiation range.