Deformable Mirror Telescope for Variable Focal Length Aberration Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current space telescopes with single focal lengths, such as the Korsch type telescope, face limitations in achieving high image quality across varying focal lengths due to geometric aberrations like astigmatism and coma, and existing solutions for focal length adjustment are either bulky or require additional optical elements, limiting their effectiveness for large pupil diameters and wide fields of view.
Innovation Solution
A telescope design featuring three multifocal aspherical mirrors with a deformable mirror that introduces specific aberrations to correct for astigmatism and coma, allowing for variable focal lengths while maintaining a compact and high-quality imaging system, using Fringe Zernike polynomials to optimize the surface shape of the deformable mirror and adjust the conicity of the mirrors to achieve improved image quality across multiple focal lengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-focal-length telescope design is used, then the optical system is simple and compact, but the image quality deteriorates when focal length needs to be adjusted due to geometric aberrations
Solution Approach 1:
The patent employs a deformable mirror whose surface shape can be dynamically adjusted to different focal lengths. The mirror transitions from a static surface to a dynamic one that can adapt its curvature and aspheric coefficients (k1, k2, k3) to maintain optimal image quality across multiple focal lengths, resolving the contradiction between system simplicity and image quality consistency.
Solution Approach 2:
The patent changes the physical parameters of the deformable mirror surface by modifying its aspheric coefficients (k1, k2, k3) and curvature radii (R1, R2, R3) to accommodate different focal lengths. This parameter adjustment allows the single optical system to maintain high image quality across multiple focal lengths without adding complex optical elements.
2Adaptability or versatility
If additional optical elements are added to adjust focal length, then focal length variability is improved, but the device complexity and size increase
Solution Approach 1:
The deformable mirror serves multiple functions: it acts as the primary focusing element, corrects geometric aberrations, and enables focal length adjustment. This single multi-functional component replaces what would traditionally require multiple separate optical elements, achieving focal length variability without increasing device complexity.
Solution Approach 2:
The patent extracts the focal length adjustment function from separate mechanical zoom mechanisms and integrates it into the deformable mirror's surface control system. This consolidation eliminates the need for additional optical elements while maintaining the ability to vary focal length continuously.
3Manufacturing precision
If a deformable mirror is used to correct aberrations, then image quality is improved, but the device complexity increases due to additional control mechanisms
Solution Approach 1:
The patent merges the aberration correction function with the focal length adjustment function into a single deformable mirror control system. By combining these functions, the control mechanism achieves dual purposes without requiring separate control systems, thereby improving image quality while minimizing the increase in device 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
The solution enables a compact, high-quality telescope with a single detector that maintains excellent image quality for large pupil diameters and wide fields of view, effectively correcting aberrations and allowing for continuous focal length adjustment without the need for additional optical elements, thereby overcoming the limitations of existing technologies.
Implementation Method 1
a deformable mirror (MD), whose surface (S) can be modified, in order to introduce a first type of aberration, in particular spherical aberration, and a second type of aberration, in particular focusing
Data Source
Figure 1
Figure 2a~2b
Figure 3a~3b
AI summary
The invention relates to an anastigmat telescope with three aspherical mirrors comprising: - means (5) for linear displacement of the third mirror (M3) on the optical axis of the telescope (O) so as to vary the focal length of the telescope between a minimum focal length (fmin) and a maximum focal length (fmax), - a deformable and controllable mirror (MD), - means (10, 10') for varying the optical path between the deformable mirror (MD) and the detector (D), - the third mirror having a new taper (c'3) determined from an initial taper (c3), the initial taper (c3) being determined from the Korsch equations, the new taper (c'3) being determined such that the telescope exhibits, without the presence of said deformable mirror and for the minimum and maximum focal lengths, aberrations compensable by said deformable mirror (MD),- said fixed median position (Pm) of said deformable mirror and the shape of its surface respectively for the minimum (Smin) and maximum (Smax) focal lengths, being determined so as to correct said compensable aberrations and to optimize the image quality in the focal plane of the telescope according to a predetermined criterion.