scholarly journals Refractive index and dispersion of butterfly chitin and bird keratin measured by polarizing interference microscopy

2011 ◽  
Vol 19 (24) ◽  
pp. 24061 ◽  
Author(s):  
Hein L. Leertouwer ◽  
Bodo D. Wilts ◽  
Doekele G. Stavenga
Keyword(s):  
Refractive Index ◽  
Interference Microscopy

Correct ray-tracing analysis for interference microscopy of fibres

1995 ◽  
Vol 450 (1938) ◽  
pp. 23-36 ◽  
Keyword(s):  
Refractive Index ◽  
Ray Tracing ◽  
High Speed ◽  
Nonlinear Least Squares ◽  
Fibre Surface ◽  
Refractive Index Profile ◽  
Initial Result ◽  
Interference Microscopy ◽  
Radial Density ◽  
Round Cross Section

A ray-tracing analysis for calculating, by means of interference microscope data, the radial distribution of refractive index, n ( r ), for fibres of round cross section has been formulated, solved, tested and used to determine n ( r ) for high-speed direct-spun polyethylene terephthalate (PET) fibres. The formulation was based on work by Kahl & Mylin (1965) originally performed to explore the radial density profiles in cylindrically symmetrical explosions. The equations were formulated with proper boundary conditions at the fibre surface, correcting a fundamental error that has caused problems for 20 years. This correct boundary condition unfortunately made it impossible to invert, as had been done in all previous work, the resulting integral equations, which consequently were solved by a nonlinear least-squares approximation. The analysis corrected a serious problem noted in the literature: namely, that the refractive index profile obtained for a particular fibre depended on the refractive index of the immersion liquid used to make the measurement. Refractive index profiles observed for PET fibres produced by high-speed direct spinning had concave-down curvature, the opposite of expectations based on previous work. This initial result suggests that when direct-spun, under crystallizing conditions, PET fibres develop a mainly radial density or quench profile, whereas fibres spun under conditions that give little crystallinity have a mainly radial orientation gradient. Experiments to test this suggestion further have not been done yet.

Effect of Vibration on Drawing and Annealing of High- Speed Spun Poly(trimethylene terephthalate) Fiber

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Kyoung Hou Kim ◽  
Yang Hun Lee ◽  
Hyun Hok Cho ◽  
Takeshi Kikutani
Keyword(s):  
Mechanical Properties ◽  
Refractive Index ◽  
High Speed ◽  
Elastic Recovery ◽  
Physical Property ◽  
Interference Microscopy ◽  
Fiber Axis ◽  
Low Density ◽  
Hot Drawing ◽  
Trimethylene Terephthalate

AbstractThe physical properties of poly(trimethylene terephthalate) (PTT) fibres were improved by means of vibration in the hot-drawing and annealing, which may be caused by the developed molecular packing. For high-speed spun PTT fibers, it was not until at the take-up speed of 3~4 km/min that the orientation induced crystallization started to emerge due to extensional stress occurred in spin line; confirmed from the results of WAXD and DSC. The PTT fibers obtained at the take-up speeds of 2~3 km/min and then drawn and annealed with vibration possessed low density and weight-crystallinity, but their birefringence was especially high. Moreover, the estimation of both refractive index parallel and normal directions to fiber axis using the interference microscopy showed that the refractive index parallel to the fiber axis was very high, which enhanced the mechanical properties of PTT fiber. Accordingly, the well-oriented chains along the fiber axis allow the PTT fiber to have better physical property such as elastic recovery although the PTT fiber has low density and crystallinity compared to PET and PBT. In effect, the PTT fiber possesses lower birefringence of over 10 times than those of PET and PBT due to its chain conformational characteristics. Therefore, we do suggest that the structural assessment against the subsequent mechanical properties according to various processes in the PTT fiber is preferred to be estimated through the respective refractive indices of parallel and normal to the fiber axis rather than conventional methods such as birefringence, crystallinity, and crystalline orientation.

Laser interference microscopy of amphibian erythrocytes: impact of cell volume and refractive index

2011 ◽  
Vol 244 (3) ◽  
pp. 223-229 ◽  
Author(s):  
A. I. YUSIPOVICH ◽  
M. V. ZAGUBIZHENKO ◽  
G. G. LEVIN ◽  
A. PLATONOVA ◽  
E. Y. PARSHINA ◽  
...  
Keyword(s):  
Refractive Index ◽  
Cell Volume ◽  
Interference Microscopy ◽  
Laser Interference ◽  
Laser Interference Microscopy

scholarly journals Topography and refractometry of sperm cells using SLIM

2017 ◽  
Author(s):  
Lina Liu ◽  
Mikhail E. Kandel ◽  
Marcello Rubessa ◽  
Sierra Schreiber ◽  
Mathew Wheeler ◽  
...  
Keyword(s):  
Refractive Index ◽  
Interference Microscopy ◽  
Phase Imaging ◽  
Label Free ◽  
Quantitative Phase Imaging ◽  
Ensemble Averaging ◽  
Thickness Profile ◽  
Light Interference ◽  
Phase Sensitive

AbstractCharacterization of spermatozoon viability is a common test in treating infertility. Recently, it has been shown that label-free, phase-sensitive imaging can provide a valuable alternative for this type of assay. Here, we employ spatial light interference microscopy (SLIM) to decouple the thickness and refractive index information of individual cells. This procedure was enabled by quantitative phase imaging cells on media of two different refractive indices and using a numerical tool to remove the curvature from the cell tails. This way, we achieved ensemble averaging of topography and refractometry of 100 cells in each of the two groups. The results show that the thickness profile of the cell tail goes down to 150 nm and the refractive index can reach values of 1.6 close to the head.

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