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Updated: Jun 20, 2026
07:03
In Situ Measurement of Vacuum Window Birefringence using 25Mg+ Fluorescence
Published on: June 13, 2020
Summary
Imperfect collimation in Fizeau wavemeters can be minimized. Proper illumination and a sealed air wedge achieve wavelength precision approaching 1 part in 10^8, eliminating the need for dispersion correction.
Area of Science:
- Optics and Photonics
- Metrology and Measurement Science
Background:
- Fizeau wavemeters are crucial for precise wavelength measurements.
- Imperfect collimation and spherical wavefront curvature can introduce significant errors.
- Dispersion in optical components necessitates correction, complicating measurements.
Purpose of the Study:
- To analyze the impact of imperfect collimation on Fizeau wavemeter fringe separation.
- To identify optimal conditions for minimizing wavelength errors.
- To assess the potential of sealed air wedges for high-precision wavelength determination.
Main Methods:
- Theoretical calculation of fringe separation under imperfect collimation.
- Analysis of wavefront curvature effects from beam expanders.
- Modeling of illumination strategies relative to wedge geometry.
- Evaluation of sealed air wedge performance.
Main Results:
- Illumination normal to the wedge face and parallel to the axis minimizes wavelength errors to 1 part in 10^8.
- Spherical wavefront curvature effects become negligible under these conditions.
- No dispersion correction for the wedge plate is required.
- A sealed air wedge demonstrates wavelength precision nearing 1 part in 10^8.
Conclusions:
- Optimized illumination and beam expansion significantly reduce Fizeau wavemeter errors.
- Sealed air wedges offer a path to ultra-high precision wavelength measurements.
- The proposed method simplifies Fizeau wavemeter design and calibration.
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