Abstract

A previous paper [Appl. Opt. 52, 6364 (2013) [CrossRef]  ] presented experimental work on the stress-optical effect in the terahertz frequency range. Although the theoretical model of experimental measurement is correct, there are two errors in the original version. As a result, the presented experimentally measured value of the refractive index-stress coefficient $A$ of polytetrafluoroethylene (PTFE) is erroneous. This erratum points out the errors in the original paper and reports the correct values.

© 2016 Optical Society of America

In [1], the phase delay caused by Poisson effect is expressed using Eq. (16), in which $N_0=1.417$ represents the original refractive of polytetrafluoroethylene (PTFE). Here, $N_0$ should minus the air refractive index, i.e., 1. As a result, the correct expressions of Eqs. (16) and (18) should be

(1)$${\delta }_d=-\frac{2\pi f(N_0-1)\mathrm{\Delta }d}{c},$$

(2)$$\mathrm{\Delta }N=\frac{c}{2\pi d}\frac{\mathrm{\Delta }\delta }{f}+\frac{(N_0-1)\mu \sigma }{E}.$$

In addition, the used value of Young’s modulus $E$ is 168.5 MPa. This is a wrong value. The correct value should be 468.5 MPa.

After adopting the mentioned two corrections, the experimental results of the stress-optic coefficient $A$ of PTFE are presented in the following Table 1 and Fig. 1

Table 1. Refractive Index-Stress Coefficient of Experiments

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Fig. 1. Values of ΔN under different stresses.

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REFERENCE

1. L. A. Li, W. Song, Z. Y. Wang, S. B. Wang, M. X. He, J. G. Han, and L. Q. Cong, “Active modulation of refractive index by stress in the terahertz frequency range,” Appl. Opt. 52, 6364–6368 (2013). [CrossRef]