When fringe meets finesse : compact iodine stabilized lasers in two colour length interferometry

Abstract
This master's thesis focuses on developing a feedback loop system for stabilizing semiconductor lasers to low-pressure iodine gas absorption spectra. The goal is to generate stable wavelengths at 531 𝑛𝑚 and 688 𝑛𝑚, essential for precise two-colour length measurement interferometry in laboratories. Semiconductor lasers are versatile light sources with broad applications in telecommunications and scientific instrumentation. However, for accurate length measurement interferometry, a stable wavelength source is vital. The thesis proposes a feedback loop system that achieves relative frequency stability levels of 10^9 by utilizing low-pressure iodine gas absorption spectra to stabilize the lasers. The research involves creating a compact device using commercially available diode lasers and short iodine cells, resulting in a footprint of 15 𝑐𝑚 𝑥 15 𝑐𝑚 𝑥 10 𝑐𝑚 . Experimental evaluations demonstrate an uncertainty of 3 𝑀𝐻𝑧, a relative frequency stability in the order of 10^9 for both the green and red lasers with an Allan deviation in the order of 10^10 and 10^9 for the green and red lasers, respectively, making the system suitable for practical applications, including gauge block measurements. This work contributes to the advancement of two-colour length measurement interferometry by providing a compact and stable wavelength generation system. The research opens up possibilities for enhanced accuracy and reliability in scientific and industrial applications.
Main Author
Format
Theses Master thesis
Published
2023
Subjects
The permanent address of the publication
https://urn.fi/URN:NBN:fi:jyu-202309155139Käytä tätä linkitykseen.
Language
English
License
In CopyrightOpen Access
Copyright© The Author(s)

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