Standard of flatness: its application to Fabry-Perot interferometers

Area of Science:

• Optical Engineering
• Materials Science
• Metrology

Background:

• Standard flats are essential for precise optical measurements.
• Previous materials may exhibit deformation or lack long-term stability.
• The need for highly stable and precise reference surfaces in optical testing.

Purpose of the Study:

• To report the initial development of liquid and solid standard flats.
• To evaluate the surface planarity and stability of polished CER-VIT.
• To assess the long-term performance of these standard flats under operational conditions.

Main Methods:

• Polishing a 100-mm diameter cylindrical block of CER-VIT.
• Measuring surface planarity using interferometric techniques.
• Monitoring the surface for deformation over a one-year period.

Main Results:

• The polished CER-VIT surface demonstrated exceptional planarity.
• Deviation from a perfect plane was less than lambda/270 over a 70-mm diameter.
• No measurable deformation was observed in the standard flat after one year of use.

Conclusions:

• CER-VIT is a suitable material for creating highly stable standard flats.
• The developed standard flats meet stringent planarity requirements for optical applications.
• Long-term stability ensures reliable performance in metrology and optical testing.