Effective Cleaving Parameters for Multimode Gradient Index CYTOP Polymer Fiber

We experimentally address simple, low-cost and effective methods for the cleaving of multimode CYTOP optical fibers using razor blades. The quality of fiber end-face preparation depends on various parameters. The necessity of the near-field intensity pattern inspection for adequate evaluation of cleaved fiber end-faces is demonstrated. Razor blades of different manufacturers are evaluated for manual cleaving, as well as automated cleaving with controlled speed and temperature. The cleaving technique with both slowed motion of the razor blade and increased temperature up to 90 °C demonstrated the best quality of fiber end-faces. Typical cleaving defects are highlighted, whereas the cleave quality was characterized in terms of the light intensity profile emitted by the fiber in near field

Multimode Fiber Interferometer Based on Graded-Index Polymer CYTOP Fiber

In this article, we present an investigation of a multimode fiber interferometer based on a multimode gradient index perfluorinated polymer fiber. The interferometric response of the polymer fiber was investigated for fiber lengths of 20, 80, and 400 m when fibers were subjected to different perturbation types, such as temperature and strain. The results were theoretically investigated using the averaged characteristics approach and compared with those for silica fiber. Practical features specific to polymer fiber multimode interferometers are discussed. The averaged transfer function was measured and compared with theory at two wavelengths. The influence of fiber length on the interferometer's properties was investigated

Multimode CYTOP fiber interferometric response to laser wavelength scanning

In this paper, we experimentally investigate the response of CYTOP-based multimode fiber interferometer to variations of the laser’s wavelength. We analyze the interferometric signals of the polymer CYTOP fiber with core diameter of 50 μm for lengths of 1 to 20 meters, using a commercially available FBG interrogator operating for wavelengths from 1510-1590 nm. The analysis was implemented using the averaged characteristics approach. In addition, the results of this work were compared with those of obtained using a silica-based multimode fiber interferometer

Gamma-radiation enhancement of sensing properties of FBGs in a few-mode polymer CYTOP fiber

We investigate the effect of γ-radiation on temperature (T) and relative humidity (RH) sensitivities of polymer perfluorinated fiber Bragg gratings (FBGs). To this aim, different γ-radiation doses (80, 120, 160, and 520 kGy) were applied to a set of FBGs. We show that irradiated FBGs demonstrate an RH sensitivity rise with the received dose: from 13.3 pm/%RH for a pristine FBG up to 56.8 pm/%RH for a 520-kGy dose at 30℃. In contrast, T sensitivity decreases with radiation dose with a subsequent change of sign from positive to negative. Therefore, by experimental interpolation, T sensitivity can be eliminated at around a 160-kGy dose. This opens the possibility of designing an RH sensor with enhanced sensitivity, which at the same time is insensitive to T