Interferometric techniques for measuring dimensional stability of passive etalons.

Area of Science:

• Metrology and Optical Engineering
• Materials Science

Background:

• Passive Fabry-Perot etalons are critical optical components.
• Dimensional stability is crucial for precision applications.
• Low expansion materials are often employed to minimize thermal drift.

Purpose of the Study:

• To present novel methods for assessing the dimensional stability of passive Fabry-Perot etalons.
• To investigate etalons utilizing spacers made from low expansion materials.
• To establish measurement precision relative to primary length standards.

Main Methods:

• Employing interferometric techniques to monitor optical path length changes.
• Utilizing a Krypton 86 primary length standard for calibration.
• Defining measurement precision as the ratio of optical length (L) to the smallest detectable change (ΔL).

Main Results:

• Demonstrated a method for investigating dimensional stability.
• Achieved measurement precision on the order of 1 part in 10^8.
• Validated the use of low expansion materials for stable etalon construction.

Conclusions:

• The described methods provide high-precision assessment of etalon dimensional stability.
• Traceability to the Krypton 86 standard ensures measurement accuracy.
• Low expansion materials are suitable for fabricating dimensionally stable Fabry-Perot etalons.