Спектральные характеристики наклонного отражательного интерферометра как сенсора показателя преломления

The paper presents simulation of the refractive index sensor of the analyzed liquid in the Kretschmann configuration based on an oblique reflective interferometer (RI) and its spectral properties for the first time. The principle of operation of this sensor is based on the effect of inverted surface plasmon resonance (ISPR). The sensitive structure is the metal-dielectric multilayer coating based on a nickel thin film in combination with non-quartewavelength dielectric layers. Modeling of the RI manufacturing process under oblique light incidence is described. Formulas for estimating the sensitivity and spectral width of the reflection maximum of ISPR are given, as well as the figure of merit. It is shown that due to the high quality factor, this type of sensor can have very large figure of merit (>10^3).

Влияние термического отжига на свойства многослойных зеркал Mo/Be

The influence of thermal action on X-ray optics performance and structure of films and transition regions in multilayer Mo/Be mirrors optimized for a reflection maximum in the interval 11.2–11.4 nm at normal incidence has been considered. The annealing temperature reached 300°C and the annealing time was 1 and 4 h. It has been shown that after thermal annealing in vacuum for 1 h at 300°C, the reflection coefficient rises; however, when the annealing time grows to 4 h, it drops. Grains in molybdenum films become finer, and the profiles of transition regions change from exponential to linear. The period of multilayer mirrors has remained the same under all annealing conditions.

Method for Synthesis of Retro-Reflective Coatings with Specified Optical Properties

One of the main trends shaping the industry today is the development of application methods for various special coatings. Among a large number of coatings, retro-reflective coatings stand out: they are used in a variety of applications throughout the industry. The processes of retro-reflective surface forming have been studied rather thoroughly. The retro-reflective performance depends mainly on structural and optical properties, as well as properties of the radiation source itself. A method was developed to synthesize retro-reflective coatings with specified optical properties using the reflectors in the form of glass microspheres. Retro-reflective performance of the coatings was studied. The paper uses different approaches to microsphere packaging in the bonding layer. It was demonstrated that the half-widths of the scattering patterns of retro-reflective coatings with different structures were quite close, and the reflection maximum of the designed coatings approached the reflection maximum of the commercial “3M” film at the same allowable viewing angles.

Optics of the ultraviolet reflecting scales of a jumping spider

The jumping spider Cosmophasis umbratica from Singapore is strongly sexually dimorphic. The males, but not the females, reflect ultraviolet as well as green–orange light. The scales responsible for this are composed of a chitin–air–chitin sandwich in which the chitin layers are three-quarters of a wavelength thick and the air gap a quarter wavelength (where λ =600 nm, the peak wavelength of the principal reflection maximum). It is shown that this configuration produces a second reflectance peak at approximately 385 nm, accounting for the observed reflection in the ultraviolet. Other scales have a similar thickness of chitin but lack the air gap and thus produce a dull purple reflection. This novel mechanism provides the spiders with two colour signals, both of which are important in mating displays.

Determination of Alloy Composition in the GaAs—InAs System by Reflectivity

The composition of GaAs—InAs alloys can be determined by measuring the position of the E1 reflection maximum in the visible spectrum range. The composition is directly related to the energy value associated with the reflection peak. The reflection technique is rapid and nondestructive. The precision and accuracy of the method is good.

SELECTIVE REFLECTION FROM MERCURY VAPOR AT HIGH PRESSURES

Selective reflection from mercury vapor in the region of the 2537 Å resonance line was investigated at pressures up to 340 atm. using reflection cells of special design. The results were interpreted on the basis of the classical theory of reflection from an absorbing medium. By fitting calculated curves to the experimental reflection contours, values of the oscillator strength, f, and the damping constant, γ, were determined. The f values so obtained are density-dependent and at high pressures are approximately equal to one half the value for the free atom. As predicted by theory, the damping constant varies directly as the density of the atoms in the vapor. This result contradicts the earlier work of Welsh, Kastner, and Lauriston (1950) in which it was concluded that γ varies as the square root of the density. A subsidiary reflection maximum was observed at 2540 Å; it is attributed to Hg2 molecules which occur in relatively large concentrations at high densities. Some preliminary observations on the selective reflection at the 1850 Å resonance line were made up to 4.4 atm.