Abstract

A brief derivation of formulas for the transmittance of flat plates, uncoated and coated, is presented. Data showing the increased near infrared transmittance of seven flat samples resulting from quarter-wave coatings of MgF₂ and LiF on their surfaces is presented. Five were coated to maximize transmittance for a wavelength of 2 microns, and two had coatings to maximize transmittance at 3.6 microns wavelength. Thick coatings of MgF₂ do not adhere well. The coatings had absorption bands, possibly due to H₂O. Estimates are made of the refractive indices of MgF₂ and synthetic sapphire in the near infrared.

© 1956 Optical Society of America

Mirror Coatings for Low Visible and High Infrared Reflectance*

Georg Hass, H. H. Schroeder, and A. F. Turner
J. Opt. Soc. Am. 46(1) 31-35 (1956)

Wear Resistance of Magnesium Fluoride Films on Glass

L. Holland and E. W. Van Dam
J. Opt. Soc. Am. 46(10) 773-777 (1956)

Semireflecting Silver Films for Infrared Interferometry*

Uri Oppenheim
J. Opt. Soc. Am. 46(8) 628-633 (1956)

Rapid and Accurate Measurements of Refractive Index in the Infrared*

E. D. McAlister, J. J. Villa, and C. D. Salzberg
J. Opt. Soc. Am. 46(7) 485-487 (1956)

New Variable Thickness Infrared Cell and the Infrared Spectra of HF, DF, H₂O, and D₂O†

Richard M. Adams and J. J. Katz
J. Opt. Soc. Am. 46(10) 895-898 (1956)