Synthesis of High-Tg Azo Polymer and the Optimization of its Poling Condition for Stable EO System

1997 ◽  
Vol 488 ◽  
Author(s):  
Takashi Fukuda ◽  
Hiro Matsuda ◽  
Takao Shiraga ◽  
Masao Kato ◽  
Hachiro Nakanishi
Keyword(s):  
Second Harmonic ◽  
Critical Factor ◽  
Optical Nonlinearity ◽  
Preparation Technique ◽  
Poling Condition ◽  
Azo Polymer ◽  
Long Time ◽  
New Material ◽  
Corona Poling ◽  
Dipolar Orientation

AbstractA new material for second-order nonlinear optics was synthesized, which was a copolymer of N-phenylmaleimide, 4-isopropenylphenol and 4'-[N-ethyl-N-(4-isopropenylphenoxyethyl) amino]-4”-nitroazobenzene (PMPD). PMPD films were poled by corona-poling technique. The optical nonlinearity of poled PMPD was measured by second harmonic generation (SHG) and electro-optic (EO) effect, and it was demonstrated that this polymer had large optical nonlinearity and a very long-time stability, as was expected. These properties were thought to be sufficient enough for practical EO devices. On the other hand, from the viewpoint of the sample preparation technique, poling conditions were investigated in order to achieve the highest possible dipolar orientation. As a result, it was found that the relationship between the electric resistance of polymer film and substrate was a critical factor for corona-poling efficiency. From a simple model, it was suggested that the poled PMPD film prepared onto the glass substrate with a resistance of ˜0.8 GΩ (at 160 °C) exhibits large SHG and EO coefficients, more than ˜500 × 10−9 e.s.u (d33 at λ = 1.064 μm) and ˜70 pm/V(r33 at λ = 632.8 nm), respectively. It should be noted that this expected values are approximately twice as much as obtained under conventional corona-poling conditions.

OPTICAL NONLINEARITY VIA PHONONS AS AN INTERMEDIARY

2001 ◽  
Vol 10 (01) ◽  
pp. 65-77 ◽  
Author(s):  
OU FA ◽  
HE MINGGAO ◽  
WU FUGEN
Keyword(s):  
Second Harmonic ◽  
Optical Nonlinearity ◽  
Photon Absorption ◽  
Saturation Phenomenon ◽  
Sum Frequency ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Threshold Phenomenon ◽  
Anti Stokes ◽  
The Given

A new model to describe the origin of optical nonlinearity is presented. In this model, the interaction between light and medium is reduced to the coupling of photons with phonons, which occurs in the crystal lattice vibrating anharmonically. Then the optical nonlinearity originates from the nonlinear photon–phonon coupling or the interaction among phonons themselves. In this paper, more attention is drawn to the latter. By the given model, (1) degenerate and (2) nondegenerate parametric oscillations, (3) Stokes and (4) anti-Stokes Raman scattering, (5) sum-frequency and (6) second harmonic generation and (7) two-photon absorption are dealt with systematically and quantum-mechanically. The results of theoretical analysis show that the effects (1)–(4) are associated with threshold phenomenon, whereas the effects (5)–(7) with the saturation phenomenon.

scholarly journals Revision of the genus Exsuperantia Özdikmen, 2009 (Tetractinellida: Phymaraphiniidae) with description of a new species from the Atlantic Ocean

Zootaxa ◽  
2019 ◽  
Vol 4613 (1) ◽  
pp. 135-151 ◽  
Author(s):  
FRANCISCA C. CARVALHO ◽  
ANDRZEJ PISERA
Keyword(s):  
New Species ◽  
Atlantic Ocean ◽  
The Past ◽  
Phylogenetic Reconstructions ◽  
The Family ◽  
Long Time ◽  
New Material ◽  
Northeast Atlantic Ocean ◽  
The Caribbean ◽  
A New Species

Phymaraphiniidae Schrammen 1924 (Porifera: Astrophorina) is a family of lithistid demosponges that has received little attention in the past decades. The systematic problems within this family have not been addressed for a long time due to the absence of new records and material. The genus Exsuperantia Özdikmen 2009 was first described by Schmidt (1879) as Rimella to allocate the species Rimella clava, found in the Caribbean. In 1892, Topsent found what he thought to be the same species described by Schmidt in the Azores, and synonymized it with Racodiscula clava, as he thought this species belonged to the family Theonellidae Lendenfeld 1903. However, Rimella and Racodiscula belong to distinct families: Rimella to Phymaraphiniidae, and Racodiscula to Theonellidae. Due to the fact that the genus Rimella was already preoccupied by a gastropod, it was renamed as Exsuperantia. In result of the poor preservation of Schmidt’s material and the absence of new specimens, the attribution of Topsent’s specimens to the family level remained obscure. Here, we review the genus Exsuperantia based on the analysis of new material recently collected during various research expeditions in the northeast Atlantic Ocean. The comparison of these new specimens with Schmidt’s and Topsent’s type material, allowed us to assign Topsent’s specimens to a new species, Exsuperantia archipelagus sp. nov., and confirm its attribution to the family Phymaraphiniidae (not Theonellidae). Phylogenetic reconstructions using newly generated sequences of the cytochrome subunit (COI) marker also support the assignment of the new species to the family Phymaraphiniidae (not Theonellidae). 

scholarly journals Genus Delplanqueia Leraut, 2001 and D. inscriptella (Duponchel, 1836) (Lepidoptera, Pyralidae) in Italy

2019 ◽  
Vol 51 (2) ◽  
Author(s):  
M. Pinzari ◽  
M. Pinzari
Keyword(s):  
Central Italy ◽  
Separate Species ◽  
Historical Collections ◽  
Long Time ◽  
New Material ◽  
Lepidoptera Pyralidae

To verify the presence in Italy of Delplanqueia inscriptella, today accepted as a separate species from D. dilutella, we carried out the study of the historical collections of Carlo Prola and Federico Hartig and new material that was recently collected in central Italy. Both species are present in continental Italy and Sicily while only D. inscriptella in Sardinia. The bibliographic reconstruction and the examination of the Hartig’s specimens that revealed the presence of Delplanqueia cortella, for a long time considered a corso-sardinian endemism, is not reflected: the specimens in Hartig’s collection with P. cortella placement are indeed Pempeliella matilella.

Second harmonic generation and photochromic grating in guest-host polymer system containing azo amide chromophores

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Marański K. ◽  
Kucharski S. ◽  
Ortyl E ◽  
Janik R. ◽  
Nunzi J.-M. ◽  
...  
Keyword(s):  
Second Harmonic ◽  
Polymer System ◽  
Butyl Methacrylate ◽  
Aliphatic Chain ◽  
Host Matrix ◽  
First Order ◽  
All Optical ◽  
Nlo Materials ◽  
Corona Poling ◽  
Glass Surfaces

AbstractThe azo sulfonamide chromophores containing long aliphatic chain were used as active nonlinear optical (NLO) materials in films prepared by spin-coating on glass surfaces. The sulfonamides were: N-{4-[{4-[(pyrimidin-2-ylamino)sulfonyl]phenyl}diazenyl]phenyl} decanamide (Amid P); N-{4-[{4-[(1,3-thiazol-2-ylamino)-sulfonyl]phenyl}diazenyl]phenyl} decanamide (Amid T) and N-{4-[(4-nitrophenyl)-diazenyl]-phenyl}undec-10-enamide (Amid N). The host matrix was a copolymer of methyl and butyl methacrylate. The formation of diffraction grating by the guest-host system was successful only in the case of Amid N. The pitch and amplitude of the grating was 930 nm and ca. 45 nm, respectively. Quantum chemical calculations revealed that the chromophores were moderate NLO-fores showing static β values of ca. 110-130 m4/V. Two procedures were involved to align chromophores to determine first order NLO susceptibility: a) corona poling, and b) all-optical poling. The NLO coefficient d33 determined in corona poled film was 25.2, 28.6 and 93.2 pm/V for Amid P, T and N, respectively.

SECOND ORDER NONLINEAR OPTICAL PROPERTIES IN SILICA-BASED GLASS FILM WAVEGUIDES

1996 ◽  
Vol 05 (02) ◽  
pp. 189-204 ◽  
Author(s):  
S. HORINOUCHI ◽  
H. IMAI ◽  
H. YAMASAKI ◽  
K. FUKAO ◽  
G.J. ZHANG ◽  
...  
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Nonlinear Optical ◽  
Glass Composition ◽  
Second Harmonic ◽  
Optical Nonlinearity ◽  
Second Order ◽  
Time Dependent ◽  
Glass Film ◽  
Second Order Nonlinearity

Phase-matched blue second harmonic generation was observed in a corona-poled Corning 7059 glass film waveguide. The induced quadratic optical nonlinearity was examined by second harmonic generation with a time dependent decay for multi-complex of SiO 2, BaO,B 2 O 3 and/or Al 2 O 3. Glass films with every possible combination of composition were fabricated and examined, The glass composition of SiO 2- BaO-B 2 O 3 and/or SiO 2- BaO-Al 2 O 3 was found to play effective roles in maintaining the induced second order nonlinearity for a longer period of time. This is supposed to be related to distributed traps which come from complex of the glass components.

scholarly journals Seed and Embryo Germination in Ardisia crenata

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Takahiro Tezuka ◽  
Hisa Yokoyama ◽  
Hideyuki Tanaka ◽  
Shuji Shiozaki ◽  
Masayuki Oda
Keyword(s):  
Seed Germination ◽  
Seed Coat ◽  
Critical Factor ◽  
Seed Storage ◽  
Storage Conditions ◽  
Embryo Germination ◽  
Long Time ◽  
Dry Conditions ◽  
Temperature Water ◽  
Good Germination

Ardisia crenata is an evergreen shrub with attractive bright red berries. Although this species is usually propagated by seed, the seeds take a long time to germinate with conventional sowing methods. We investigated the germination capacity of seeds and embryos collected in different months and the effects of seed storage conditions, germination temperature, water permeability of the seed coat, and the endosperm on seed germination. Seeds and embryos collected in late September or later showed good germination rates. Seeds germinated more rapidly after longer periods of storage at low temperature (approximately 5°C), and those stored in dry conditions showed lower emergence frequency than those stored in wet conditions. Seeds germinated at 15–30°C, but not at 5–10°C. Removal of the seed coat enhanced water uptake and seed germination. Seeds with various proportions of the removed seed coat were sown on a medium supplemented with sucrose. The germination frequency increased as the size of the remaining endosperm decreased. However, the opposite results were obtained when seeds were sown on a medium without sucrose. We concluded that the optimal temperature of 25°C is the most critical factor for seed germination in A. crenata.

scholarly journals THE EFFECTIVENESS OF USING VIRTUAL LABORATORY WORKSHOPS IN ONLINE EDUCATION OF STUDENTS STUDYING THE DISCIPLINE “INORGANIC CHEMISTRY”

2020 ◽  
Vol 17 (36) ◽  
pp. 934-948
Author(s):  
Maria G RAYISYAN ◽  
Maria Anatolievna BORODINA ◽  
Olga Igorevna DENISOVA ◽  
Yuri Sergeevich BOGACHEV ◽  
Vladimir Dmitriyevich SEKERIN
Keyword(s):  
Inorganic Chemistry ◽  
Distance Learning ◽  
Online Education ◽  
Research Problem ◽  
Educational Process ◽  
Virtual Laboratory ◽  
Virtual Laboratories ◽  
Long Time ◽  
New Material ◽  
Education Of Students

Distance learning has already become a part of the educational process. In this regard, questions appear concerning its organization and the solution of specific problems. They include laboratory workshops, which is an integral part of the educational process in higher education since laboratory works allow students to gain knowledge and acquire skills, which is a prerequisite for the formation of their specialist competence. The problems of obtaining educational information during distance learning can be quite successfully solved. However, the acquisition of experimental skills remains an educational, scientific, and methodological problem that requires a solution. The article defines the peculiarities of using virtual laboratory workshops in the online education of students studying the discipline “Inorganic Chemistry”. The theoretic analysis of the main statements of the research problem was presented in the article. The results of the experimental study have proved that the use of computer modeling and the tools of a virtual laboratory when studying chemistry disciplines increases the educational achievements of the students, regardless of the initial level of knowledge. A prerequisite for the effective acquisition of skills by students is the systematic use of virtual laboratory tools. With the occasional use of virtual laboratory instruments, the skills obtained during the experiment were not learned or were not learned for a long time. The use of virtual laboratories provides independent training for students, increases motivation to master new material. Students focus on the experimental process, not on equipment and tools, as it happens in a real laboratory, which can become both a positive and a negative aspect of acquiring practical skills of future engineers, doctors, and pharmacists.

scholarly journals A revision of Onychelmis Hinton, 1941 (Coleoptera: Elmidae), with description of new species, DNA barcoding and notes on the geography of the genus

2021 ◽  
Vol 739 ◽  
pp. 1-35
Author(s):  
Marek Linský ◽  
Zuzana Čiamporová-Zaťovičová ◽  
Fedor Čiampor Jr
Keyword(s):  
New Species ◽  
Dna Sequences ◽  
Species Delimitation ◽  
Molecular Data ◽  
Distribution Map ◽  
Line Drawings ◽  
The Andes ◽  
Long Time ◽  
New Material ◽  
Morphological And Molecular Data

The genus Onychelmis Hinton, 1941 was for a long time regarded as a small taxon with only three known species distributed in the Andes. A study of new material from Ecuador, using morphological and molecular data, has resulted in the discovery of five new species: Onychelmis lenkae sp. nov., O. lobata sp. nov., O. minor sp. nov., O. onorei sp. nov. and O. splendida sp. nov. We also revised the entire genus and redescribed the three known species, O. longicollis (Sharp, 1882), O. leleupi Delève, 1968 and O. whiteheadi Spangler & Santiago, 1991. Habitus photographs of adults are provided, together with line drawings of male and female genitalia, and schematic illustrations of the distribution of femoral tomentum for each species. DNA sequences for barcoding the COI mtDNA fragment were used to support species delimitation and to suggest possible relationships among species. The revision includes a key to adults of all species of Onychelmis and notes on the biogeography of the genus, with an updated distribution map.

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