The incorporation of abnormal dispersion liquids into an optical design can result in significant performance advantages. However, the large thermal coefficient of refractive index which is common to all liquids (dn/dT) can complicate the athermalization of these designs. One method is to use two different liquids to form both positive and negative liquid lens elements which balance each other thermally while maintaining color correction. The success of this approach is dependent on the proper selection of materials, and on a detailed knowledge of the wavelength dependence of the refractive index thermal coefficients. The thermal dependence of refractive index and dispersion in the visible spectral region for a number of liquids was investigated. A correlation between the refractive index thermal coefficient (dn/dT) and abnormal dispersion was found to exist in a majority of liquids. The optical property measurements were made at the Vavilov State Optical Institute, St. Petersburg, Russia in collaboration with the Lockheed Palo Alto Research Laboratory, Palo Alto, California.

Date Published: 15 September 1995
PDF: 8 pages
Proc. SPIE 2540, Current Developments in Optical Design and Engineering V, (15 September 1995);

Published in SPIE Proceedings Vol. 2540:
Current Developments in Optical Design and Engineering V
Robert E. Fischer; Warren J. Smith, Editor(s)