Coaxial four-reflection optical system for visible light long-wave infrared common-aperture imaging
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Solution Overview
Problem
Existing visible light/infrared composite imaging optical systems suffer from axial length compactness issues and imaging quality degradation due to beam splitting using light filters, leading to aberrations and energy loss.
Innovation Solution
A coaxial four-reflection optical system with visible light long-wave infrared common-aperture imaging, utilizing a main reflecting mirror, first and fourth reflecting mirrors, and high-order aspherical transmitting mirrors for beam splitting and imaging, integrated to reduce axial length and improve imaging quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If beam splitting is realized using a light filter/color separation filter, then visible light and infrared imaging can be achieved, but aberration is introduced in the convergent imaging light path and additional energy loss occurs
Solution Approach 1:
The patent removes the light filter/color separation filter from the optical system and extracts the beam splitting function to a dedicated beam splitting mirror. This eliminates the harmful effects of the filter on imaging quality while preserving the composite imaging capability.
Solution Approach 2:
The patent introduces a beam splitting mirror as an intermediary component to separate visible light and infrared light paths. This mediator performs the beam splitting function without introducing aberrations or energy loss, unlike the light filter approach.
2Adaptability or versatility
If light filter/color separation filter is used for beam splitting, then visible light and infrared imaging functions are achieved, but additional energy loss occurs
Solution Approach 1:
The patent removes the light filter that causes energy loss and extracts the beam splitting function to a mirror-based system that preserves optical energy throughout the imaging path.
Solution Approach 2:
The patent replaces the optical filtering mechanism (light filter) with a mechanical reflection-based beam splitting mechanism (beam splitting mirror), which has lower energy loss characteristics.
3Length of stationary object
If axial length compactness is improved in two-reflection and three-reflection coaxial systems, then structural compactness is achieved, but imaging quality and functional density need further improvement
Solution Approach 1:
The patent designs the optical system so that mirrors serve multiple functions: the first mirror performs both visible light reflection and infrared reflection, the second mirror serves as both a beam splitting mirror and an infrared reflecting mirror, and the third mirror acts as both a beam splitting mirror and a visible light reflecting mirror. This multi-functionality increases functional density within the compact axial length.
Solution Approach 2:
The patent merges multiple optical functions into single mirror components, combining beam splitting and reflection functions in the same elements, thereby achieving higher functional density in a compact structure.
4Adaptability or versatility
If beam splitting using light filter is used, then visible light and infrared imaging is achieved, but distortion and stray light affect imaging quality
Solution Approach 1:
The patent removes the light filter that generates stray light and aberrations, and extracts the beam splitting function to mirror-based components that do not introduce these harmful factors.
Solution Approach 2:
The patent introduces beam splitting mirrors as intermediary components that separate light paths without generating the stray light and aberrations associated with light filter-based beam splitting.
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 system achieves compact structure, low distortion, and good stray light inhibition, enabling all-day spatial optical remote sensing and dynamic monitoring with improved functional density and cost performance.
Implementation Method 1
a surface of the first transmitting mirror is coated with a film to split entering light into a visible light spectral segment and an infrared spectral segment
Implementation Method 2
the main reflecting mirror, the first transmitting mirror, the third reflecting mirror and the fourth reflecting mirror are coaxially disposed and are all two-order aspherical mirrors
Data Source
AI summary
The present disclosure relates to a coaxial four-reflection optical system with visible light long-wave infrared common-aperture imaging, and belongs to the technical field of optical systems. The technical problems that the axial length compactness and the imaging quality of the visible light/infrared composite imaging system in the existing technology need to be improved are solved. The optical system of the present disclosure includes a main reflecting mirror, a first transmitting mirror, a third reflecting mirror, a fourth reflecting mirror, a second transmitting mirror, a third transmitting mirror and a fourth transmitting mirror. The optical system has a visible light panchromatic imaging function, a visible light multispectral imaging function and a long-wave infrared imaging function, which lowers the requirement of a space remote sensor for ground illumination conditions, realizes all-time space optical remote sensing reconnaissance and dynamic monitoring, and greatly improves the functional density and cost performance of a space optical load. The optical system has a compact structure, low distortion and good stray light inhibition, and is convenient to process, assemble and adjust.