The validity of the proposed model is confirmed by comparing the estimated value of the power loss with the measured value for various values of the groove depth and bend displacement.2.?Experimental SetupFigure kinase inhibitor Seliciclib 1 presents a schematic illustration of the experimental setup used to measure the power loss in the bent and elongated grooved POF specimens. The major items of equipment include a tensile test machine (EZ Test-500N, Shimadzu, Kyoto, Japan), a disc, a computer system and an optical power meter (Photom, model 205A, Tokyo, Japan). The elongation tests were performed using four discs with different radii, namely R = 5, 10, 15 and 20 mm. The POF specimens (step index type, SH-4001, Mitsubishi Rayon Company Ltd.) had a coating diameter of 2.2 mm, a cladding diameter of 1 mm, a core diameter of 0.
98 mm, and a numerical aperture (NA) of 0.5. The core, cladding and coating of these POFs were fabricated from polymethyl methacrylate (PMMA), polytetrafluoroethylene (PTFE) and low-density polyethylene (LDPE), respectively. The refractive indices of core and cladding are nco = 1.492 and ncl = 1.402, respectively. Each POF specimen had a total length of 800 mm. Prior to the elongation tests, the POF specimens were clamped in such a way as to create a gauge length of 115 mm. One of the ends of the specimen was then connected to the light source (a light emitting diode with a wavelength of 660 nm), while the other was connected to a power detector. In each test, the center of the disc was carefully aligned with the center of the POF gauge length and the disc was then displaced through a distance of 10 mm in the vertical (downward) direction.
Figure 1.Experimental setup used to measure power loss in grooved POF specimens under combined bending and elongation loading.The groove-like features in the POF specimens were produced using a grinding wheel (diamond Carfilzomib grain size: #120) and therefore had a curved profile. Figure 2 presents a geometrical model of a typical grooved specimen. As shown in Figure 2(a), the groove was formed at the mid-point position of the gauge length. Figure 2(b) presents an enlarged view of the groove geometry, in which R1 is the radius of curvature of the groove, D is the external diameter of the POF, and h is the depth of the groove as measured from the top surface of the POF. In the present study, D = 2.2 mm, R1 = 7.5 mm, and the groove depth was assigned values of h = 0, 0.7, 0.9 and 1.1 mm. The variations inhibitor licensed in attenuation and disc displacement are recorded synchronically by the power meter and the PC, respectively.Figure 2.Geometrical model of grooved POF specimen. (a) Gauge length of POF specimen with grooved section located at mid-point position. (b) Enlarged view of groove geometry.3.