Abstract
Optics and Lasers in Engineering 48 (2010) 555-560 The digital holographic interferometry (DHI) was utilized for investigating
the optical properties of polymer and optical fibers. The samples investigated
here were polyvinylidene fluoride (PVDF) polymer fiber and graded-index (GRIN)
optical fiber. The phase shifting Mach-Zehnder interferometer was used to
obtain five phase-shifted holograms, in which the phase difference between two
successive holograms is pi/2, for each fiber sample. These holograms were
recorded using a CCD camera and were combined to gain a complex wavefield,
which was numerically reconstructed using the convolution approach into
amplitude and phase distributions. The reconstructed phase distribution was
used to determine the refractive index, birefringence and refractive index
profile of the studied samples. The mean refractive index has been measured
with accuracy up to 4 {\times} 10-4. The main advantage of DHI is to overcome
the manual focusing limitations by means of the numerical focusing. The results
showed accurate measurements of the optical properties of fibers.