Abstract

A photorefractometer to determine slight changes in refractive index of a liquid is described. When a long dielectric cylinder is immersed in a specimen liquid and an axial light cone is condensed at one end, the energy transmitted by total internal reflections through the cylinder depends primarily on δ, the difference in refractive index of the rod and the surround. Thus change in index of the surround liquid is related to change in emergent flux from the immersed rod. If the photometric unit is capable of detecting 100 K% change in emergent energy, and if δ≲0.1, then changes in liquid index of K·δ can be detected. By proper choice of K and δ, a change in index of 10−6 is measurable.

An instrument based on this principle was constructed and the experimental results show good agreement with theory. The effects of absorption, reflection losses at the two ends of the rod, and partial reflection within the rod on the sensitivity of the system are studied theoretically. It also seems possible to measure the low refractive index liquids by the use of a hollow rod refractometer. Various applications of this photorefractometer principle are indicated.

© 1957 Optical Society of America

Full Article  |  PDF Article
OSA Recommended Articles
Photorefractometer I. Extension of Sensitivity and Range

N. S. Kapany and D. A. Pontarelli
Appl. Opt. 2(4) 425-430 (1963)

Photorefractometer II. Measurement of N and K

N. S. Kapany and D. A. Pontarelli
Appl. Opt. 2(10) 1043-1048 (1963)

Fiber Optics. Part I. Optical Properties of Certain Dielectric Cylinders*

N. S. Kapany
J. Opt. Soc. Am. 47(5) 413-422 (1957)

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 (12)

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

Equations (22)

You do not have subscription access to this journal. Equations 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