This review is focused on microstructured optical fiber sensors developed in recent years for liquid RI sensing. The review is divided into three parts: the first section introduces a general view of the most relevant refractometric sensors that have been reported over the last thirty years. Section 2 discusses several microstructured optical fiber designs, namely, suspended-core fiber, photoni...

In this seminar the third-order nonlinear optical phenomena are described. The emphasis is on the nonlinear refractive index n2. We describe the Z-scan technique, which is a simple method to determine n2. At the end we show how Z-scan method can be used to examine protein concentration in human blood.

We present a novel needle-based device for the measurement of refractive index and scattering using low-coherence interferometry. Coupled to the sample arm of an optical coherence tomography system, the device detects the scattering response of, and optical path length through, a sample residing in a fixed-width channel. We report use of the device to make near-infrared measurements of tissues ...

I t is known that a continuous process takes place in bone whereby mature osteones (Haversian systems) are broken down and new osteones are formed. Historadiographic study has shown that the mineral salts content of osteones increases gradually toward a maximum (1, 2, 8). In order to obtain information on the chemical and physical properties of the growing osteone, we have developed a dissectio...

We present the results of variable-angle spectroscopic ellipsometry and transmittance measurements to determine the variation of the complex refractive index of ion-implanted single-crystal diamond. An increase is found in both real and imaginary parts at increasing damage densities. The index depth variation is determined in the whole wavelength range between 250 and 1690 nm. The dependence fr...

The eye lens grows throughout life by cell accrual on its surface and can change shape to adjust the focussing power of the eye. Varying concentrations of proteins in successive cell layers create a refractive index gradient. The continued growth of the lens and age-related changes in proteins render it less able to alter shape with loss of capacity by the end of the sixth decade of life. Growt...

In this paper, a technique based on the use of optical interferometry is employed to evaluate the surface geometry and refractive index profile of a graded-index planar microlens array. The experimental setup consists of sodium light and He-Ne laser sources which are incorporated into a microscopy system. The two light sources can be utilized alternately for surface geometry and refractive inde...

This paper presents a novel optofluidic Michelson interferometer based on droplet microfluidics used to create a droplet grating. The droplet grating is formed by a stream of plugs in the microchannel with constant refractive index variation. It has a real-time tunability in the grating period through varying the flow rates of the liquids and index variation via different combinations of liquid...