Polarizing Interference Microscope Research Articles

Opto-thermal properties of fibers. XI. The effect of thermal annealing of drawing behavior for Egyptian polyester fibers on the crystallinity and some optical parameters

The structure developed of annealed Egyptain poly(ethyleneterephthalate) (PET) fibers is studied interferometerically due to the drawing process. Using a two-beam Pluta polarizing interference microscope connected to a device to dynamically study the draw ratio with the birefringence changes, the relations of drawing changes with some optical parameters are given. The evaluation of density, the mean square density fluctuation η2, crystallinity, amorphous orientation, crystalline orientation functions, number of chains per unit volume Nc, and number of random links between the network junction points N has been found. The results obtained clarify the effect of annealing time and temperature with different draw ratios on the structure of PET fibers. Empirical formula is suggested to correlate the changes in fθ, θ, Δna, and A with the draw ratio. Microinterferograms and curves are given for illustration. © 1998 John Wiley & Sons, Inc. J Appl Polm Sci 68: 1371–1386, 1998

Opto-Thermal Properties of Fibres. Part 2: Investigation of Optical Parameter Changes in Annealed and Quenched Nylon 6-6

The changes in refractive indices and birefringence of nylon 6-6 fibres with different annealing conditions were” studied by interferometry. The polarizing interference microscope was used to determine the mean refractive indices and mean birefringence of these fibres. Also, an acoustic method has been used to measure densities. The results are used to calculate some structural parameters such as the form birefringence, virtual refractive index, harmonic mean polarisability of the dielectric, and the specific refractivity of the isotropic dielectric. Also, the number of monomer units per unit volume and the refractive indices of fully oriented fibre, when using monochromatic light vibrating parallel and perpendicular to the fibre axis, were calculated and found to be 1.5543 and 1.4723. The generalized Lorentz-Lorenz equation given by de Vries was used to determine nylon 6-6 fibre structural parameters. Comparisons between Herman's optical orientation function formula and the corrected formula by de Vries are given.

Opto-Thermal Properties of Fibres. Part 2: Investigation of Optical Parameter Changes in Annealed and Quenched Nylon 6-6

The changes in refractive indices and birefringence of nylon 6-6 fibres with different annealing conditions were” studied by interferometry. The polarizing interference microscope was used to determine the mean refractive indices and mean birefringence of these fibres. Also, an acoustic method has been used to measure densities. The results are used to calculate some structural parameters such as the form birefringence, virtual refractive index, harmonic mean polarisability of the dielectric, and the specific refractivity of the isotropic dielectric. Also, the number of monomer units per unit volume and the refractive indices of fully oriented fibre, when using monochromatic light vibrating parallel and perpendicular to the fibre axis, were calculated and found to be 1.5543 and 1.4723. The generalized Lorentz-Lorenz equation given by de Vries was used to determine nylon 6-6 fibre structural parameters. Comparisons between Herman's optical orientation function formula and the corrected formula by de Vries are given.

Optothermal properties of fibers. VII. Optical investigation of annealed nylon‐6 fibers

The influence of annealing on the birefringence of nylon-6 fibers was examined. These fibers were found to show considerable optical anisotropy. Three independent techniques were used to study the optical anisotropy in these fibers. The first technique to determine the diameter of the fiber from the diffraction pattern was using a He—Ne laser beam. The second technique was the application of the Becke-line technique to study the effect of annealing on the skin layer of these fibers at different temperatures for a constant time of 5 h. The third is the application of a double-refracting interference microscope (the Pluta polarizing interference microscope). The double-beam technique is considered as the most suitable technique for determining the mean refractive indices and the double refraction of the annealed samples at different temperatures. (155 and 175°C and at two constant times 7 and 9 h). Microinterferograms and curves are given for illustration. © 1997 John Wiley & Sons, Inc. J Appl Polm Sci 65:1293–1306, 1997

Optothermal properties of fibers. VII. Optical investigation of annealed nylon-6 fibers

The influence of annealing on the birefringence of nylon-6 fibers was examined. These fibers were found to show considerable optical anisotropy. Three independent techniques were used to study the optical anisotropy in these fibers. The first technique to determine the diameter of the fiber from the diffraction pattern was using a He—Ne laser beam. The second technique was the application of the Becke-line technique to study the effect of annealing on the skin layer of these fibers at different temperatures for a constant time of 5 h. The third is the application of a double-refracting interference microscope (the Pluta polarizing interference microscope). The double-beam technique is considered as the most suitable technique for determining the mean refractive indices and the double refraction of the annealed samples at different temperatures. (155 and 175°C and at two constant times 7 and 9 h). Microinterferograms and curves are given for illustration. © 1997 John Wiley & Sons, Inc. J Appl Polm Sci 65:1293–1306, 1997

Opto-thermal properties of fibers — 2. Structural characteristics of cold drawn annealed Egyptian polyester (PET) fibers

Egyptian poly(ethyleneterephthalate) (PET) fibers in the drawn state show considerable optical and mechanical anlsotropy. The polarizing interference microscope is used with a fiber manipulation device to study, dynamically, the variation of refractive indices and birefringence of PET fibers with the draw ratio. In addition, the resulting data were used to calculate the strain optical coefficient, Poisson's ratio, the mean square density fluctuation under different annealing conditions, as well as several other parameters and constants. Also, an empirical formula has been applied to demonstrate the variation of the cross-sectional area of PET fibers with draw ratio and the constants of this formula are determined. Microinterferograms are given for illustration. The change of refractive index profile of annealed PET fibers at different conditions are also shown.

Effect of Dyeing Process on Optical Anisotropy of Polyester Fibres

A two beam interferometric technique using a pluta polarizing interference microscope has been used for the determination of the refractive index profiles and the birefringence of undyed and dyed polyester fibres with single and mixture colorants. Diameters and cross-sectional shapes of these fibres were determined from the diffraction pattern of a He-Ne laser beam, incident perpendicular to the fibre axis.

Effect of Dyeing Process on Optical Anisotropy of Polyester Fibres

A two beam interferometric technique using a pluta polarizing interference microscope has been used for the determination of the refractive index profiles and the birefringence of undyed and dyed polyester fibres with single and mixture colorants. Diameters and cross-sectional shapes of these fibres were determined from the diffraction pattern of a He-Ne laser beam, incident perpendicular to the fibre axis.

Fast, common-path, switchable, achromatic phase-shifter for polarization interferometry

Abstract A fast switchable phase-shifter using a pair of liquid-crystal devices with a switching angle of 60° is described. This phase-shifter can be placed in the common path traversed by the two orthogonally polarized beams emerging from a polarization interference microscope and used for digital phase measurements over a wide range of wavelengths. It can also be used in a stellar interferometer with orthogonally polarized beams for measurements of fringe visibility with white light.

Fast, common-path, switchable, achromatic phase-shifter for polarization interferometry

A fast switchable phase-shifter using a pair of liquid-crystal devices with a switching angle of 60° is described. This phase-shifter can be placed in the common path traversed by the two orthogonally polarized beams emerging from a polarization interference microscope and used for digital phase measurements over a wide range of wavelengths. It can also be used in a stellar interferometer with orthogonally polarized beams for measurements of fringe visibility with white light.

The Effect of Annealing on the Degree of Orientation of Nylon 6 Fibres

The polarizing interference microscope was used to study the variation of the principal optical parameters of annealed nylon 6 Fibres at 160 ± 1°C. The resulting data were used to calculate optical orientation function, the angle of orientation and the specific refractivity of the isotropic dielectric over all the annealing time range. The change of refractive-index profile of the annealed nylon 6 fibres with time at a constant temperature of 160 ± 1°C are given. Also an empirical formula is given to inter-relate the structural parameters for the annealed nylon 6 fibres.

The Effect of Annealing on the Degree of Orientation of Nylon 6 Fibres

The polarizing interference microscope was used to study the variation of the principal optical parameters of annealed nylon 6 Fibres at 160 ± 1°C. The resulting data were used to calculate optical orientation function, the angle of orientation and the specific refractivity of the isotropic dielectric over all the annealing time range. The change of refractive-index profile of the annealed nylon 6 fibres with time at a constant temperature of 160 ± 1°C are given. Also an empirical formula is given to inter-relate the structural parameters for the annealed nylon 6 fibres.

Optothermal properties of fibers. II. Annealing effect on the birefringence variations of polyester fibers

The variation of refractive indices and birefringences of Egyptian-manufactured polyester fibers with different annealing times at constant temperature 160°C are studied by inter-ferometry. The polarizing interference microscope is used for determining the mean re-fractive indices and mean birefringence of these fibers. The results are used to calculate optical orientation function and the angle of orientation. Also, the acoustic method has been used for measuring the density and the mechanical loss factor of these fibers. Relations between the mean refractive indices, birefringence, polarizabilities, mechanical loss factors, and densities with annealing time are given for these fibers. Illustrations are given using graphs and microinterferograms. © 1996 John Wiley & Sons, Inc.

Optothermal properties of fibers. II. Annealing effect on the birefringence variations of polyester fibers

The variation of refractive indices and birefringences of Egyptian-manufactured polyester fibers with different annealing times at constant temperature 160°C are studied by interferometry. The polarizing interference microscope is used for determining the mean refractive indices and mean birefringence of these fibers. The results are used to calculate optical orientation function and the angle of orientation. Also, the acoustic method has been used for measuring the density and the mechanical loss factor of these fibers. Relations between the mean refractive indices, birefringence, polarizabilities, mechanical loss factors, and densities with annealing time are given for these fibers. Illustrations are given using graphs and microinterferograms.

Opto-Thermal Properties of Fibres: 1. Effect of Annealing and Quenching Processes on the Optical Parameters of Courtelle Fibres

The effect of annealing and quenching temperatures, in the range (80–180°C), on various optical parameters has been studied for Courtelle (Courtaulds acrylic fibre) using a Pluta polarizing interference microscope. Relationships between the optical parameters at different temperatures are given for these fibres. The results obtained were utilized for calculations of the isotropic refractive indices and polarizabilities per unit volume, and relationships between these new parameters at different temperatures are given. Also, determinations of Cauchy's constants, dispersive power and the dielectric constant at infinity were carried out. The change in the refractive index profile of the annealed and quenched Courtelle fibres with temperature is given. Illustrations are given using graphs and microinterferograms.

Opto-Thermal Properties of Fibres: 1. Effect of Annealing and Quenching Processes on the Optical Parameters of Courtelle Fibres

The effect of annealing and quenching temperatures, in the range (80–180°C), on various optical parameters has been studied for Courtelle (Courtaulds acrylic fibre) using a Pluta polarizing interference microscope. Relationships between the optical parameters at different temperatures are given for these fibres. The results obtained were utilized for calculations of the isotropic refractive indices and polarizabilities per unit volume, and relationships between these new parameters at different temperatures are given. Also, determinations of Cauchy's constants, dispersive power and the dielectric constant at infinity were carried out. The change in the refractive index profile of the annealed and quenched Courtelle fibres with temperature is given. Illustrations are given using graphs and microinterferograms.

Optothermal properties of fibers. VI. Effect of annealing on some of the optical and dynamic mechanical parameters of polyester fibers

Changes in the structure of annealed polyester fibers (Egyptian manufacture) at a constant time of 5 h and different temperatures (80-190°C) were studied interferometrically. The Pulta polarizing interference microscope was used for determining the mean refractive indices and mean birefringence of these fibers. The multiple-beam Fizeau fringes in transmission was also used for determining the refractive indices of the skin and core of these fibers. Also, the acoustic method was used for measuring the density and mechanical loss factor of these fibers. Relations between the mean refractive indices, birefringences polarizabilities per unit volume, and mechanical parameters of annealed polyester fibers with different temperatures are discussed to clarify the thermal effects. Illustrations are given using graphs and microinterferograms.

Opto-thermal properties of fibres. 1. Effect of annealing on the optical parameters of nylon 6 fibres

Changes in the structure of annealed Nylon 6 fibres at a constant temperature of 160 °C and at different times were studied interferometrically. The Pluta polarizing interference microscope was used to determine the mean refractive indices and mean birefringence of these fibres. Relationships between the mean refractive indices, birefringence, isotropic refractive index and polarizabilities per unit volume with different times are given for these fibres. An empirical formula is suggested to represent the variation of birefringence of annealed Nylon 6 fibres with different times. Illustrations are given using graphs and microinterferograms.

Opto-mechanical properties of fibres. 6. Structural characteristics and optical properties of PE fibres

The polarizing interference microscope is used with a fibre manipulation device to study, dynamically, the variation of refractive indices and birefringence of PE fibres with the draw ratio. The resulting data were used to calculate Poisson's ratio over all strain ranges. In addition, the strain optical coefficient and some other parameters and constants were calculated. Also, an empirical formula is applied to demonstrate the variation of the cross-sectional area of PE fibres with draw ratio and the constants of this formula are determined. Microinterfrograms are given for illustration.

Optothermal properties of fibers. I. Relations between optical properties and change of the density and mechanical loss factor for annealed polyester fibers

AbstractPolyester (Egyptain manufacturers) fibers were annealed in the temperature range 80–190°C for time intervals from 1 to 10 h. The density of the annealed fibers was measured by a system based on the theory of vibrating strings. The fiber diameter was also determined, using the laser forward diffraction technique. Refractive indices and birefringence for annealed fibers at different temperatures and constant time, 1 h, were measured by the polarizing interference microscope. The behavior of fiber density and the mechanical loss factor at different annealing temperatures and times were discussed at different optical parameters. The results obtained clarify the effect of annealing time and temperatures on the optical, density, and mechanical loss factor behavior of polyester fibers. Microinterferograms are given for illustration. © 1995 John Wiley & Sons, Inc.