Aspherical Mirrors for Spectrometer Light Yield
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Solution Overview
Problem
Conventional spectrometers with cylindrical mirrors suffer from suboptimal light yield for weak emission lines, as the light is not efficiently focused onto the detectors.
Innovation Solution
The use of tilted mirrors with aspheric surfaces, specifically parabolic or elliptical curvature, improves the imaging characteristics and light focusing, enhancing light yield and reducing scattered light by better adapting to the geometrical conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If cylindrical mirrors with spherical curvature are used to focus light onto detectors, then the device structure is simple and easy to manufacture, but the light yield is suboptimal for weak emission lines
Solution Approach 1:
The patent replaces spherical mirrors with aspherical mirrors that have parabolic or elliptical curvature profiles. This change in surface geometry allows the mirrors to better focus divergent light beams from the diffraction grating onto the linear detector array, significantly improving light yield while maintaining manufacturing feasibility through precision glass molding techniques.
2Device complexity
If cylindrical mirrors are used to deflect and focus light, then the optical path is simple, but the imaging characteristics are not well adapted to geometrical conditions
Solution Approach 1:
The aspherical mirror surfaces with parabolic or elliptical curvature are specifically designed to match the geometric conditions of the Paschen-Runge spectrometer configuration. The mirrors are tilted at specific angles and positioned to optimize the mapping between the dispersed spectrum and the linear detector, improving spectral resolution and imaging accuracy without adding complex optical components.
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 significantly improves light yield and reduces scattered light, ensuring that more light of specific wavelengths reaches the detectors, enhancing the analytical capabilities of the spectrometer.
Implementation Method 1
The beam path between the diffraction grating and the sensors is illustrated in more detail in FIG. 2. Here, schematically the concave diffraction grating is illustrated as a cross section from which a number of beams run parallel to one another onto an imaging mirror. The imaging mirror has a surface turned towards the beams, which has a highly-reflective surface
Implementation Method 2
The reflecting surface focuses the light beams onto a light-sensitive element of the CCD sensor line. The light yield is substantially improved in the case of this geometric arrangement in contrast to known spectrometers, in which the light beams are to be focused via cylindrical mirrors onto the CCD line
Implementation Method 3
The light is guided through an entrance gap into the interior of the spectrometer and there strikes a diffraction grating, which spectrally fans out the light in one plane and images the entrance gap onto lines of solid body sensors
Data Source
AI summary
The invention relates to a spectrometer for analyzing the optical emission of a sample, having an excitation source, an entrance gap and a dispersive element, which fans out the spectrum of the light generated in the excitation source in a plane, and having solid body sensors with one or more lines, which are arranged in the region of the focal curve of the beam path in order to evaluate the spectral information, wherein the sensors are arranged above or below the plane and the spectral emission is deflected onto the sensors by mirrors and focused, wherein the reflecting surface of the mirrors is aspherically formed in a direction of curvature.