The holographic grating recording process in thin films of amorphous azobenzene-functionalized polymers has been widely reported the literature. In spite many reports, little is known about mechanisms responsible for different temporal behaviors diffraction efficiency during long times. Here, we report on experimental studies changes photochromic polymer. gratings were inscribed four polarization combinations beams: s-s, p-p, s-p and right to left circular (RCP-LCP) employing degenerate...

Amplified spontaneous emission (ASE) phenomenon in the 6-nitro-1′,3′,3′-trimethylspiro[2H-1-benzopyran-2,2′-indolin] organic dye dispersed a solid matrix has been observed. The biopolymer system deoxyribonucleic acid blended with cationic surfactant molecule cetyltrimethyl-ammonium chloride served as matrix. ASE appeared under sample excitation by UV light pulses (λ=355 nm) coming from nanosecond or picosecond neodymium doped yttrium aluminum garnet lasers and reinforced green (λ=532...

In this paper, we present results of detailed studies on amplified spontaneous emission (ASE) and lasing achieved in a double-layer system consisted biopolymer based matrix loaded with 3-(1,1-dicyanoethenyl1)-1phenyl-4,5dihydro-1H-pyrazole organic nonlinear optical dye photochromic polymer. The laser action was via distributed feedback configuration third order Bragg scattering surface relief grating generated To excite the luminescence, have used 6 ns pulses Nd:YAG at 532 nm. ASE thresholds...

Abstract In the report we demonstrate how, using laser light, effectively trap gas bubbles and transport them through a liquid phase to desired destination by shifting beam position. The physics underlying effect is complex but quite general as it comes from limited two-dimension, well-known, Marangoni effect. experimental microscope-based system consists of thin layer placed between two glass plates containing dye dissolved in solvent light that strongly absorbed dye. This point-like heat...

Kinetics of thermal <italic>cis–trans</italic> isomerization the single-component azobenzene-based phototropic liquid crystal in its isotropic and nematic phases is studied.

Abstract The linear electro‐optic (Pockels) effect in a series of alkali metal acid phthalate crystals has been studied. Single coefficients r and for sodium (NaAP), potassium (KAP) rubidium (RbAP) phthalates have measured by employing the modified Mach–Zehnder interferometric technique. best crystal this is RbAP with = 9.10 × 10 −12 m V −1 , 3.05 sizable figure merit phase retardation, comparable that KDP. dispersion properties KAP are discussed detail.

We investigate an amplified spontaneous emission phenomenon and lasing in a two-layer system: layer of modified deoxyribonucleic acid (DNA) polymeric matrix containing dye which is superimposed on periodic relief structure formed photochromic polymer. The luminescent was prepared from DNA blended with cationic surfactant molecule cetyltrimethyl-ammonium chloride (CTMA) Rhodamine (Rh6G) laser dye. This covered specially designed polymer surface grating inscribed by holographic method order to...

Gas bubbles can be trapped and then manipulated with laser light. In this report, we propose the detailed optical trapping mechanism of gas confined inside a thin light-absorbing liquid layer between two glass plates. The necessary condition bubble in case is direct absorption light by solution containing dye. Due to heat release, fluid whirls propelled surface Marangoni effect at liquid/gas interface emerge extend large distances. We report experimental microscopic observation origin an...

The paper presents a series of azobenzene and azo pyridine compounds containing hydroxyl or 6-hydroxyhexyloxyl substituents. nitrogen atom is located at the ortho-, meta- para-position in structure derivatives. impact structural features chromophores on their thermal (DSC, TGA) optical (UV–Vis) properties was investigated. dark cis–trans isomerization kinetics studied ethanol chloroform 298 K. formation noncovalent hydrogen bonds between molecules and/or chromophore-solvent monitored using...

Holographic grating recording in azobenzene-based polymers using a single coherent light of specific wavelength (monophotonic recording) is the basis majority applications this type material. Here, we report new approach to holographic that uses two sources having different wavelengths during process (biphotonic recording). The efficiency was improved significantly compared monophotonic recording. results, by presenting simple way increase process, have important implications for materials....

Efficient coherent light amplification with a very high net exponential gain Γ≈2600 cm−1 has been observed in sandwich-type hybrid-polymer–liquid-crystal structures. The is result of an energy exchange between two beams two-beam coupling experiment. reported coefficient measured tilted sample configuration within Raman–Nath diffraction regime at electric fields the order 1 V/μm.

In this paper, we present strong enhancement of optical properties hybrid liquid crystal structures functionalized with metallic and semiconductor nanoparticles. Several experiments done in two wave mixing experimental set-up have reported that diffraction efficiency can be improved by up to 14 times introducing nanoparticles cadmium selenide or gold into the photoconducting polymer adjacent layer. Our research may open a possible route for development faster more efficient holographic...

The formation of the surface relief gratings (SRG) in azo-polymers strongly depends on polarization configuration writing beams. So far s–s has been considered as ineffective terms SRG formation. Here, we report that very high-amplitude SRGs can be recorded when using inscription geometry supramolecular polymer–azobenzene complexes and efficiency process molecular weight polymer. Furthermore, a single holographic irradiation leads to grating (primary grating) and, unexpectedly, secondary...

Phototropic liquid crystals (PtLC) are a new class of materials possessing number potential applications in photonics devices. However, so far significant majority PtLC has been realized by the doping classical crystal with photochromic dye. The photochemical phase transition such systems was investigated mainly monitoring changes transmittance. In this study, single-component phototropic using holographic grating recording combination polarized optical microscope. cis–trans...

In this paper, we present the results of doping nematic liquid crystals (nLCs) with semiconductor quantum dots (QDs) where discuss CdS and CdSe QDs influence on optical properties investigated crystal structures, i.e., diffraction efficiency enhancement. We also mathematical model describing interaction between nLC molecules in volume. The aim study is to improve comprehension mechanisms photorefractive effect observed functionalized which can lead development more efficient holographic...

The paper reports on the formation of surface relief gratings in thin films azobenzene-functionalized polymer. We evidence that efficiency process strongly depends length main polymer chains case s-s configuration. explanation this relationship is given and based revealing differences ability motion chain which strictly related to its length.

The family of Mn-based organic–inorganic hybrids has greatly expanded due to their advantages in applications. They also show superior bright and size-tunable photoluminescence can be considered a perfect alternative toxic lead-based compounds. In this work, we present the detailed structural, optical, electrical characterization ([(NH3CH2CH2)3NH])2[MnBr5]Br5. title compound exhibits unique type inorganic arrangement created by trigonal bipyramids. It crystallizes noncentrosymmetric space...