Lithium niobate double channel Fabry-Perot interferometer for solar corona uses

Area of Science:

• Physics
• Astronomy
• Optics

Background:

• Solar corona emission lines provide crucial data on solar plasma.
• Accurate measurement of spectral profiles is essential for astrophysical analysis.
• Existing methods may face challenges with scattered light and spectral stability.

Purpose of the Study:

• To investigate the efficacy of a tunable etalon for measuring solar corona emission line profiles.
• To assess the performance of a lithium niobate etalon in a specific spectral range.
• To evaluate methods for removing instrumental and sky-scattered light.

Main Methods:

• Utilized a tunable etalon made of y-cut lithium niobate.
• Employed a voltage-controlled tuning mechanism for spectral scanning (+/-1000 V for +/-1 A).
• Implemented polarization chopping and differential measurement between ordinary and extraordinary rays to remove scattered light.

Main Results:

• Achieved a passband of 0.2 A with a free spectral range of 6 A.
• Demonstrated minimal spectral drift (<0.05 FWHM) for a temperature excursion of 0.05 degrees C.
• Successfully removed scattered light components, ensuring accurate line profile measurements.

Conclusions:

• The tunable lithium niobate etalon is a viable tool for precise solar corona emission line spectral profiling.
• The implemented polarization chopping technique effectively mitigates scattered light interference.
• The system exhibits excellent thermal stability, crucial for accurate astrophysical measurements.