A new method of determining objectively the amount scattered light in an optical system has been developed. It is based on measuring degree polarization images formed after a double pass through system. dual apparatus composed modified double-pass imaging polarimeter and wave-front sensor was used to measure properties aberrations under test. We studied accuracy procedure that included lanthanum-modified lead zirconate titanate (PLZT) ceramic plate able generate variable amounts as function...

Questionnaires have been used as research tools to provide a standardized approach assess quality of life at various time periods and populations. However, literature shows only few articles about self-reported color vision changes. Our aim was evaluate the subjective patient feelings before after cataract surgery compare results with test result. method follows: 80 patients filled out modified questionnaire performed Farnsworth-Munsell 100 Hue Color Vision Test (FM100) before, two weeks,...

We produced a set of pseudoisochromatic plates for determining individual color-difference thresholds to assess test performance and properties, analyzed the results. report high validity classification ability deficiency type severity level (comparable that fourth edition Hardy–Rand–Rittler (HRR) test). discuss changes acceptable chromatic shifts from protan deutan confusion lines along CIE xy diagram, correlation red–green discrimination index. Color vision was tested using an Oculus HMC...

Color vision tests can give information about pathological changes in eye structures. The purpose of our research was to study the color sensitivity and visual acuity before after cataract surgery. We used a saturated Farnsworth D15 arrangement test check confusion line directions. is easily perceptible (essential eldery patients), it possible tritan, protan, deutan results were analyzed several ways: by summing differences between adjacent caps according Bowman averaging difference vectors...

An imaging polarimeter in transmission has been used to explore the effects of scatter and depolarization induced by a polymer dispersed liquid crystal cell. The experiment was carried out for three visible wavelengths. Both directional scattered component can be distinguished light transmitted this material. Whereas increased with voltage, portion decreased. This common behaviour all polarimetric analysis revealed that degree polarization also affected changes voltage applied Depolarization...

Small-size PLZT 8.5/65/35 ceramic modulators with the length of 4-6 mm are used to obtain Q-switched pulses Er:YAG lasers-the pulsewidth 150 ns, energy single pulse up 5 mJ, if followed by a number small-intensity postlasing pulses-the total is 10 mJ.

Abstract The studies of modulators for infrared made transparent PLZT ceramics are reported. Two types light discussed: 1) using the transversal electrooptic effect and 2) longitudinal (EO) electrostriction. latter has been as an electric field controllable Fabry-Perot interferometer. characteristics provided.

Abstract Polymer dispersed liquid crystals with electrically induced variations of light scattering extent similar to that transparent PLZT ceramics are used for simulation different development stages eye cataract. Wavelength dependencies determined in the visible spectral range, and human visual response looking through obstacle onset various spatial frequency stimuli is psychophysically electrophysiologically order find correlation between extent, acuity evoked potential VEP chromatic...

The present work reports on spectral transmission and scattering dependencies, the status of scattered light polarization for PLZT ceramics elements working in electrically induced longitudinal mode. Experiments are done with double optical integrated sphere technique. Several devices using controlled effect developed - eye occluders studies dynamics visual stereoscopic response, an artificial model to simulate transfer function cataract lens.

The study of chromostereopsis has gained attention in the backdrop use computer displays daily life. In this context, we analyze illusory depth sense using planar color images presented on a screen. We determine difference threshold required to induce an psychometrically constant stimuli paradigm. Isoluminant are screen, which aligned along blue-red line display CIE xyY space. Stereo disparity is generated by increasing between central and surrounding areas with both consisting random dots...

Highly refractive and transparent lead–lanthanum zirconate titanate (PLZT) ceramics are used for an output coupler of the erbium yttrium scandium gallium garnet laser (λ=2.79 μm) that simultaneously serves as electro-optic Q switch. The optical aperture such a dual-function PLZT element was 6×6 mm2 thickness 3 mm. For switching, short ≈3 μs negative voltage pulses (1500–1800 V) were applied to positively direct current biased (≈1400 element. Single-pulse lasing with pulse half width 160–170...

Abstract The IR reflectivity of PLZT (Pb0.9025La0.0975Zr0.65Ti0.35O3) and PSN (Pb(Sc0.5Nb0.5)O3) ceramics was determined in the spectral range 15 to 2000 cm−1 temperature region 25 200°C around ferroelectric phase transitions. Kramers-Kronig analysis used calculate dielectric function. In case a strong central-mode-type dispersion observed both BWO transmission below ∼ 40 which prevents softening lowest phonon mode. less diffusive central mode is shifted 10 monotonous whole range.

Abstract The structure-properties relationships and phase transitions in perovskite ceramics, films of PLZT, PLZST, PST, PSN, PMNT compounds are discussed with regard to ordering, relaxor behaviour, pronounced ferroelectric, electromechanical electrocaloric properties. theoretical approach is extended the time dependent Ginsburg-Landau model. evolution dielectric properties relaxors after change temperature electric field creating an increase permittivity found follow a logarithmic law...

Disability glare, affecting e.g. road safety at night, may result either from intraocular light scattering or external conditions such as fog. Measurements were made of in fog and compared with straylight data for normal eyes simulated cataract. All measurements a direct compensation flicker method. To estimate levels fog, carried chamber different densities Density was characterized by the meteorological term visibility V ranged 7 to 25. Test distance constant 5 m. Cataract eye placing...

Q-switching of the Er:Cr:YSGG laser at 2.79 micrometers is realized using electrooptic modulators PLZT X/65/35 ceramics. The high (but slow as compared with single crystals) electrooptical effect in allowed to construct Q-switches an aperture larger than 4 X mm<SUP>2</SUP>, small lengths 3 - 6 mm, a control voltage 1000 1500 V. two modes--as (lambda) /2 switch placed into cavity Brewster angle avoiding reflection losses and /4 higher pass due Fresnel reflections. A output was obtained...

PLZT 8.75/65/35 ceramics modulators are developed for solid state infrared lasers used in medicine. The halfwave voltage U/sub /spl lambda//2/ the cw Nd:YAG (1.06 mu/m) laser DC mode electrooptic modulation is 1450 V, and modulator size 5/spl times/5/spl times/6 mm/sup 3/. For Er:YAG pulse modulation, has a of 4/spl times/6/spl times/18 3/, 1350 V with 300 bias. By 150 mu/s long pulses rise decay times less than 5 can be achieved.

In recent years, phase retrieval methods recovering the of an object from coded diffraction patterns have gained popularity. A numerical method called PhaseLift that recovers a very limited number was recently proposed. Performance has been analyzed for different types and masks modulating object. We present unique application uses four rotations single mask, only amplitude simulations, screen with root-mean-square (RMS) value 0.294 μm used as test The RMS retrieved after smoothing 0.257 μm....

The article focuses on the process of water warming from 0 °C in a glass. An experiment is performed that analyses temperature top and bottom layers during warming. experimental equipment very simple can be easily set up using devices available schools. curves obtained help us to understand convection glass determine at which density maximum. In addition, computational fluid dynamics—CFD modeling carried out facilitate better comprehension phenomenon observed experiment.

The change of the scattering coefficient in mid-infrared (IR), as compared to visible region, is estimated from theory electromagnetic wave inhomogeneous dielectric media. It has been found that light by domains and grains at a wavelength λ = 5 μm decreased factor about 102 its value 0.5 μm. Experimental studies have performed on electrooptic (EO) properties ferroelectric ceramics PLZT 10/65/35, sample thickness being up 15 mm. Dispersion EO effect IR region studied 8/65/35 PSN temperatures...

The purpose of this study was to investigate visual depth perception real physical colour stimuli with red-green and blue-yellow opponency. We modified the Howard–Dolman stereotest where subjects should determine closer two bars emitting light definite placed in front a CRT monitor served as background. Two-alternative forced-choice paradigms were used threshold values. Thresholds close 5–10 arcsec for luminance contrast revealed both stimuli. A term, stereosensitivity – reciprocal magnitude...

The aim of the study is to determine best printing technology for creation colour vision deficiency tests. Valid tests protanopia and deuteranopia were created from perceived matching experiments printed samples by deficient individuals. Calibrated EpsonStylus Pro 7800 printer ink prints Noritsu HD 3701 digital photographic used. Multispectral imagery (by tunable liquid crystal filters system CRI Nuance Vis 07) data analysis show that in case prints, measured pixel coordinate dispersion (in...

Abstract Optical bistability in PLZT ceramics due to the Ar+ laser induced heating and changes of optical thickness a plane parallel plate (behaving as Fabry-Perot cavity) is observed. Such used also an extracavity mirror. Thermooptical tuning mirror causes non-liner behaviour such system. A negative feedback brought by thermooptic can be stabilise output. On contrary, competitive action coupled mirror, on one hand, non-linear cavity, other cause periodical fluctuations output laser.

In the current study, we address phase retrieval of one-dimensional objects from near-field diffraction patterns using multiple-plane Gerchberg–Saxton algorithm, which is still widely used for retrieval. The algorithm was implemented in a low-cost digital signal processor capable fast Fourier transform Q15 arithmetic, by previously mentioned algorithm. We demonstrate similarity between objects, i.e., vectors cut out map tertiary spherical aberration retrieved and these are measured with...