Features of the optical medium of the surface of plant seeds

It was found that the integumentary tissue of plant seeds has the property of enhancing luminescence light. This phenomenon manifests itself in both the time and frequency domain. The gain factor (in power), depending on the type of seed, varies from 1.7 (beans) to 2.6 (rye). To determine it, the optical medium of the plant seed surface was represented as a dynamic link having an input and output. The impulse (time) characteristic of the link was found by the relaxation curve of luminescence. The dependence of the gain on temperature is expressed in the fact that when it decreases from 50 oC to –30 oC, the gain increases from 1.73 to 2.48. This phenomenon can be explained by the fact that at the stage of relaxation of luminescence, the absorption coefficient of the optical medium of the seed surface takes a negative value

Optical Angular Sensor for Space Applications

This paper describes a silicon/glass sensing structure for axial angle measurements. The presented optical angular sensor can statically measure the angle φ of any apparatus depending on the torsion of the optical component against the sensor housing. Core element of the sensor is an optical medium with an etched structure, which diffracts light from an LED according to the Fresnel equation. Two photodiodes, one for angle determination and one as reference, conduct the measurement. Hence, the signal splits up into two parts: one part transmits trough the optical system and the second part (the reflected wave) is used as reference signal. For self-referencing purposes, the wavelength spectrum of the LED has its maximum in the infrared regime near to the wavelength where silicon gets transparent (l~1000 nm). More precisely, torsion angle and light intensity show a dependency given by Tstot if a straight etching structure (refraction profile) is used. To avoid multiple reflections of light, a coating layer restricts the illuminated area in the optical medium. With this setting a resolution of 0.05-degree rotation angle has been achieved and by stacking the construction, the sensor can measure an angular range from 30° up to 270°.

The Physiology of Tear Film

The precorneal tear film is a thin layer, about 2–5.5 μm thick, which overlays the corneal and conjunctival epithelium. It functions to lubricate and protect the corneal and eyelid interface from environmental and immunological factors as well as provide an optical medium. The tear film is depicted as a three-layered structure: lipid, aqueous, and mucous layers. Within each layer possesses a different composition which dictates its function. In common between the three layers are their homeostatic process of evaporation and drainage. Any dysfunction in either of the layers can result in Dry Eye Syndrome (DES). The composition, regulation, and pathology of tear film will be discussed in this chapter.

GRAIN DESCRIPTION BY A RANDOMLY INHOMOGENEOUS OPTICAL MEDIUM MODEL FOR THE INTERLABORATORY MATCHING OF VITREOUSNESS MEASUREMENTS

Currently, due to the appearance of instrumental objective methods for determining grain vitreousness, it is possible to ensure the uniformity of measurements of this indicator in a number of laboratories. The article proposes a model for describing grain as an inhomogeneous optical medium and an interpretation of the vitreousness index as a characteristic of light scattering. A method for calculating the parameters of mathematical model and estimating the scattering coefficient using an RGB camera is presented. It is shown that the implementation of the grain vitreousness measurements based on the scattering coefficient makes possible to obtain a satisfactory reproducibility in between-lab measurements.

Magneto-optical spin Hall effect of light controlled by thermo-optical effect

In this paper, an experimental method of magneto-optical spin Hall effect of light (MOSHEL) based on thermo-optical control is designed. First, we design and implement a pilot experiment—the SHEL experiment controlled by thermo-optical. According to the experiment, it is concluded that the increase of the temperature of the thermo-optical medium will have an important influence on the corresponding thermo-optical spin Hall effect of light (TOSHEL). Accordingly, we designed a device that controls the SHEL in magneto-optical-thermo-optical (MO-TO) two-dimension that uses the thermo-optical effect to simultaneously control the intrinsic TOSHEL and MOSHEL.