Abstract

Capacitance cells have been designed and constructed for measuring the low-frequency dielectric constant of nonmetallic samples such as optical materials. One equipment covers the 80–300-K temperature range and the other, the 300–500-K range. Data are reported for optical materials CaF₂, KCl, ZnS, and MgF₂ (measured parallel to c axis) and a reference material: Teflon sheet. Only Teflon has been measured in both temperature ranges. A special feature of the equipment is that the dielectric cell can easily be replaced by a cell adapted to measure the linear thermal expansion of appropriate samples through the same temperature ranges, and these measurements permit improved determinations of the temperature coefficient of the dielectric constant.

© 1984 Optical Society of America

Low Temperature Thermal Expansion Measurements on Optical Materials

James Steve Browder and Stanley S. Ballard
Appl. Opt. 8(4) 793-798 (1969)

Thermal expansion data for eight optical materials from 60 K to 300 K

James Steve Browder and Stanley S. Ballard
Appl. Opt. 16(12) 3214-3217 (1977)

Thermal Expansion Measurements on Four Optical Materials from Room Temperature to 10 K

James Steve Browder and Stanley S. Ballard
Appl. Opt. 11(4) 841-843 (1972)

Apparatus for Measuring the Thermal Expansion of Optical Materials from 30°C to 250°C

John F. Ebersole, Stanley S. Ballard, and James Steve Browder
Appl. Opt. 11(4) 844-848 (1972)

Thermal expansion uniformity of materials for large telescope mirrors

Stephen F. Jacobs, Dean Shough, and Cliff Connors
Appl. Opt. 23(23) 4237-4244 (1984)