Measurement of the spectral dispersion curves of low birefringence polymer fibres

Investigation of Weakly Oriented Polymeric Objects by Extended Fringe Field Interference Method

“…Figures 6-8 demonstrate the comparison between the spectral dispersions of the aromatic polyamide fiber birefringence and directional refractive indices using the multi-fringe VAWIOFT [10], the extended VAWIFFI and Pluta's methods. It is worth noting that there is not any uncertainty in identification of the interference orders using the current extended VAWIFFI method A. M. Sadik and D. Litwin compared to the previous conventional VAWI methods [4,6,12]. It is not necessary to start or carry out the experiment at certain wavelengths.…”

“…The variable-wavelength interferometry, which has been developed by many researchers, is one of the most successful approaches [1][2][3][4][5][6][7][8][9][10][11][12]. Pluta applied three different developed methods to determine the initial and current interference orders in the images of fringe field, uniform fringe field and optical Fourier transform of the highly birefringent under study [4,6].…”

“…Hamza et al suggested an interferometric method based on the fringe field interference variable-wavelength interferometry for determination of the initial interference order in the image of low birefringent fiber [12]. The disadvantage of this method is that the position of the initial coincidence is needed and the value of initial interference order is approximated to be an integer number.…”

“…This method is based on variable-wavelength fringe field interference (VAWIFFI) technique 518 A. M. Sadik and D. Litwin for investigating weakly oriented polymeric objects. Using this method, there is no need to start with or obtain the coincident and anticoincident positions for measurement of the initial interference order as in conventional interferometric methods [6,12]. This leads to the decrease of the global error in the determination of the initial interference order in the image of the weakly oriented polymeric object.…”

Optoelectronic Techniques for Surface Characterization of Fabrics

“…It may be explained by the cohesion process. Although fibres in the fibrous background are not melted, heat can modify their own structure and more particularly their birefringence (Hamza et al, 2007;Chand et al, 2001). That is why study has to be conducted by comparing a ratio of different directions.…”