Catadioptric Optical Assembly for Laser Radar Stability
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Solution Overview
Problem
Existing laser radar systems suffer from system instability and polarization issues due to a large rotating scanning mirror, which limits the ability to focus different wavelengths simultaneously and restricts the field of view, necessitating a more stable and compact optical assembly.
Innovation Solution
A compact optical assembly using catadioptric optics that moves as a unit with the laser radar system, eliminating the need for a large scanning mirror by folding the optical path with a concave mirror and incorporating a reflective window or cold mirror to align the camera's optical axis with the measurement beam, allowing simultaneous focus of different wavelengths and reducing system size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a large rotating scanning mirror is used to achieve beam pointing, then the field of view is covered, but system stability deteriorates and polarization issues occur
Solution Approach 1:
The patent removes the large rotating scanning mirror from the optical path entirely. Instead, a small fixed scanning mirror is used in combination with a movable optical assembly that can translate and rotate, extracting the problematic large mirror while maintaining beam pointing capability through alternative means.
Solution Approach 2:
The movable optical assembly performs multiple functions: it translates to adjust the optical path length, rotates to change the beam pointing direction, and houses both the scanning mirror and camera. This multi-functional design replaces the single large scanning mirror's functions while improving stability.
2Ease of operation
If a large rotating scanning mirror is used, then beam pointing is achieved, but device complexity and size increase
Solution Approach 1:
The optical assembly is segmented into distinct functional components: a fixed portion containing the laser source and beam splitter, and a movable portion containing the scanning mirror and camera. This segmentation allows the complex functions to be distributed and managed separately, reducing overall system complexity.
Solution Approach 2:
The patent introduces translational motion in addition to rotational motion. The movable optical assembly can translate along the optical axis to adjust path length independently of the rotational scanning motion, adding a dimensional degree of freedom that simplifies the optical design and reduces complexity.
3Productivity
If conventional optics are used, then the system can operate, but different wavelengths cannot be focused simultaneously
Solution Approach 1:
The scanning mirror is positioned at a specific location in the optical path where it can reflect both the pointing beam and measurement beam wavelengths effectively. The movable optical assembly is designed with local optical properties that accommodate multiple wavelengths, allowing simultaneous focusing through precise positioning and orientation.
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 provides a stable and compact optical assembly that enables simultaneous focusing of pointing and measurement beams, enhances system stability, and expands the field of view by eliminating the need for a large scanning mirror, improving the accuracy and efficiency of laser radar systems.
Implementation Method 1
The optical assembly includes catadioptric optics that fold the optical path of a pointing beam and a measurement beam
Implementation Method 2
incorporating a reflective window or cold mirror to align the camera's optical axis with the measurement beam
Data Source
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AI summary
An optical assembly for a system for inspecting or measuring of an object is provided that is configured to move as a unit with a system, as the system is pointed at a target, and eliminates the need for a large scanning (pointing) mirror that is moveable relative to other parts of the system. The optical assembly comprises catadioptric optics configured to fold the optical path of the pointing beam and measurement beam that are being directed through the outlet of the system, to compress the size of the optical assembly.