Grism-Based Wavenumber Linearity Dispersion Optical System
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Solution Overview
Problem
Existing optical systems for achieving high wavenumber linearity are either too complex, large in size, have low energy utilization, or are excessively costly, particularly when using combinations of gratings and prisms or introducing free-form surfaces.
Innovation Solution
A design method for a wavenumber linearity dispersion optical system that includes a grating, prism, and objective lens, where the grating adjoins the prism, with adjustments to the vertex angle of the prism and optimization of the objective lens to minimize linearity errors and aberrations, allowing for higher wavenumber linearity without increasing system size or cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the grating and prism are separated to achieve linear wavenumber distribution, then the linearity is improved, but the system size and assembly difficulty increase
Solution Approach 1:
The patent merges the grating and prism into a single integrated component called a grism, where the grating is directly mounted on the prism. This combination achieves linear wavenumber distribution without requiring the grating and prism to be separated, thereby maintaining high linearity while reducing system size and simplifying assembly procedures
2Measurement precision
If two gratings are used for joint beam splitting to achieve linear wavenumber distribution, then the linearity is improved, but the energy utilization decreases
Solution Approach 1:
Instead of using two separate gratings for joint beam splitting, the patent combines a grating with a prism into a single grism component. This single-component approach achieves linear wavenumber distribution while avoiding the energy losses associated with multiple grating reflections and transmissions, thereby improving energy utilization
3Measurement precision
If free-form surfaces are introduced to achieve higher wavenumber linearity, then the linearity is improved, but the cost increases excessively
Solution Approach 1:
The patent achieves linear wavenumber distribution by combining standard optical components (grating and prism) into a grism, avoiding the need for complex free-form surfaces. This approach maintains high linearity while using conventional manufacturing techniques, thereby keeping costs reasonable and avoiding excessive manufacturing 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
This approach achieves higher wavenumber linearity with improved energy utilization and reduced system size, while maintaining a lower cost, by compensating for distortion and chromatic aberrations in the objective lens, resulting in a more efficient and compact optical system.
Implementation Method 1
Collimated light is split through the grating and the prism into rays of different wavenumbers
Implementation Method 2
Collimated light is split through the grating and the prism into rays of different wavenumbers
Implementation Method 3
rays of different wavenumbers enter the objective lens at different angles and image on an image plane
Data Source
AI summary
The invention discloses a design method of a wavenumber linearity dispersion optical system and an imaging spectrometer, including: building an optical system including a grating, a prism and an objective lens that are sequentially arranged, the grating adjoins the prism; defining a linearity evaluation coefficient RMS; assigning a minimum value to the linearity evaluation coefficient RMS through adjustment to the vertex angle of the prism, when the linearity evaluation coefficient RMS is at minimum, the vertex angle of the prism being α1; acquiring compensations for distortion and longitudinal chromatic aberration of the objective lens based on the interval between equal-difference wavenumbers on the image plane when the vertex angle of the prism is α1; and optimizing the objective lens based on the compensations for distortion and longitudinal chromatic aberration of the objective lens to obtain an optimized optical system. Higher wavenumber linearity can be achieved through objective-lens-aberration compensated wavenumber linearity.