| 摘要 |
<p>In the determination of the refractive index profile of an optical fibre by measuring the intensity of a light beam reflected from points on an end face of a fibre, spurious signals due to reflections in the optical system used and interference effects caused by their interaction with the beam are avoided by plane polarizing the transmitted beam, and placing a .pi./2 phase shifting device adjacent the fibre end face so that the reflected beam is polarized orthogonally to the transmitted beam, whereby spurious components in the received beam can be removed by a suitably oriented polarizer.</p> |
