Simple Method for Measuring Small Retardance

N. N. Nagib; A. W. Abdallah; M. S. Bahrawi; H. Osman; N. A. Mahmoud; E. S. Mousa

doi:10.33094/journal.140.2018.11.1.3

Authors

N. N. Nagib National Institute for Standards, Giza, Egypt
A. W. Abdallah National Institute for Standards, Giza, Egypt
M. S. Bahrawi National Institute for Standards, Giza, Egypt
H. Osman Physics Department, Faculty of Science, Cairo University, Giza, Egypt
N. A. Mahmoud National Institute for Standards, Giza, Egypt
E. S. Mousa Physics Department, Faculty of Science, Cairo University, Giza, Egypt

DOI:

https://doi.org/10.33094/journal.140.2018.11.1.3

Keywords:

Retardance measurement, Small retardance, Accuracy of measurement.

Abstract

Small retardances are encountered in many experimental works. Internal stresses, weakly birefringent materials, optical windows and formation of contaminating surface layers are sources of small retardances. Most known methods for retardance measurements fail to determine accurately their values which are sometimes essential in the evaluation of experimental results. In this work, we present a method for accurate measurement of a small retardance. Our study aims to find the retardance error in a birefringent full-wave plate which, if perfect, is considered as of zero retardance. Our treatment will make use of a previously presented model for simultaneous calibration of two phase plates.