Abstract

In order to obtain highest reflectance with Al + MgF2 and Al + LiF coatings at λ2161 Å and λ1026 Å, respectively, the thickness of the dielectric films must be precisely controlled. This paper presents a method of monitoring the thickness of thin MgF2 and LiF films on freshly evaporated Al films by measuring the reflectance of the Al surface at λ1216 Å as the dielectric films are being deposited. A specially designed hydrogen discharge lamp with a MgF2 window is used as the light source, and an NO ionization chamber, also with a MgF2 window, serves as the detector. This combination results in an essentially monochromatic response at λ1216 Å. Reflectances of about 85% at λ1216 Å were obtained by overcoating freshly deposited Al with MgF2 films that had an effective optical thickness of λ/2 at λ1216 Å. With the same monitoring system, the thickness of LiF on Al could also be precisely controlled and LiF-overcoated Al mirrors with reflectances higher than 71% at both λ1026 Å and λ1216 Å were consistently prepared.

© 1972 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
Preparation of Mirror Coatings for the Vacuum Ultraviolet in a 2-m Evaporator

A. P. Bradford, G. Hass, J. F. Osantowski, and A. R. Toft
Appl. Opt. 8(6) 1183-1189 (1969)

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (6)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Tables (1)

You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Metrics

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription