Cylindrical Lens Array Spectroscope Moire Pattern Resolving Power
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Solution Overview
Problem
Conventional spectrometers face a trade-off between measurement band and resolving power, with narrow bands offering high resolving power but at the cost of increased light quantity loss, limiting the improvement of spectrum resolving power, especially when measuring weak light.
Innovation Solution
Incorporating a cylindrical lens array as a fringe former or moire pattern former in the spectroscope to reduce the width of high-intensity regions and minimize light quantity loss, thereby enhancing spectrum resolving power without blocking input light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the width of the high-intensity region of the moire pattern is reduced to improve resolving power, then the aspect ratio of the slit array must be increased, but this reduces the opening ratio and increases light quantity loss
Solution Approach 1:
The patent replaces the traditional mechanical slit array structure with a moire pattern formation mechanism. Instead of using narrow slits to define the high-intensity region width, the invention uses the interference pattern between two periodic structures (first and second fringes) to create the moire pattern. This substitution allows the width of the high-intensity region to be controlled by the pitch difference between the two fringe arrays rather than by physical slit dimensions, thereby maintaining high resolving power without the light loss associated with narrow slits.
Solution Approach 2:
The patent changes the controlling parameter for the high-intensity region width from physical slit width to the pitch difference between the first and second fringe arrays. By adjusting the pitch parameters (pitch1 and pitch2) of the two periodic structures, the width of the resulting moire pattern's high-intensity region can be precisely controlled without modifying physical aperture sizes. This parameter transformation enables independent optimization of resolving power and light throughput.
2Measurement precision
If the slit width is reduced to improve the aspect ratio and resolving power, then the measurement precision improves, but the light quantity loss increases making it difficult to measure weak light
Solution Approach 1:
The patent replaces the mechanical slit array structure with a moire pattern formation mechanism. Instead of using narrow slits to define the high-intensity region width, the invention uses the interference pattern between two periodic structures (first and second fringes) to create the moire pattern. This substitution allows the width of the high-intensity region to be controlled by the pitch difference between the two fringe arrays rather than by physical slit dimensions, thereby maintaining high resolving power without the light loss associated with narrow slits.
Solution Approach 2:
The patent changes the controlling parameter for the high-intensity region width from physical slit width to the pitch difference between the first and second fringe arrays. By adjusting the pitch parameters (pitch1 and pitch2) of the two periodic structures, the width of the resulting moire pattern's high-intensity region can be precisely controlled without modifying physical aperture sizes. This parameter transformation enables independent optimization of resolving power and light throughput.
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 cylindrical lens array configuration reduces light quantity loss to one-tenth of traditional slit arrays, allowing for improved spectrum resolving power and downsizing of the spectroscope by eliminating the need for additional lenses.
Implementation Method 1
On the cylindrical lens array, light incident on each cylindrical lens is condensed onto a corresponding line
Implementation Method 2
a diffraction grating 14, and a second slit array 17. The first slit array 12 has a plurality of slits arranged with a first pitch p1. The diffraction grating 14 is a reflection grating characterized by a diffraction angle that changes with respect to a light wavelength (angular dispersion)
Implementation Method 3
a moire pattern former that forms a moire pattern by overlaying the first fringes that have been dispersed, on second fringes having a second pitch different from the first pitch
Data Source
AI summary
A spectroscope for measuring a spectrum of input light includes a fringe former that forms first fringes having a first pitch by splitting the input light, a diffraction grating that disperses each of the first fringes, a moire pattern former that forms a moire pattern by overlaying the first fringes that have been dispersed, on second fringes having a second pitch different from the first pitch, and an image pickup device that measures the spectrum of the input light by detecting the moire pattern. At least one of the fringe former and the moire pattern former includes a cylindrical lens array.