We presented the results of a study on the luminescent and lasing characteristics of active photoexcitable planar waveguides made of polymethyl methacrylate (PMMA) doped with 3-(diethylamino)-7-oxo-7H-benzo[45]imidazo[12-a]chromeno[32-c]pyridine-6-carbonitrile. Changes in the position of the maxima of the lasing lines for waveguides obtained from different solvents with respect to the values obtained in solutions were noted under excitation by the second harmonic of an YAG-Nd3+ laser.

The results of a study of the luminescent and generation characteristics of an active photovoltaic planar waveguide made of polymethylmethacrylate (PMMA) doped with borofluoride complexes of 2,2'-bisBODIPY are presented. The features of the spectral characteristics in a toluene solution and a thin-film waveguide made of PMMA doped with 2,2'-bisBODIPY are noted. The photostability value of 2,2'-bisBODIPY in the PMMA film is significantly higher than the photostability value in the toluene solution. Threshold characteristics of laser generation in the planar waveguide made of PMMA doped with 2,2'-bisBODIPY are investigated. It is shown that near the generation threshold in an active planar waveguide, the generation line first narrows and then, the radiation intensity exponentially increases.

"Работы по поиску твердотельных лазерно-активных сред на красителях, имеющих характеристики, сравнимые с их жидкими аналогами, актуальны до сих пор. Одновременно с развитием твердотельных лазерных систем с лазерно-активными элементами в виде полимерных блоков, ведутся интенсивные работы по созданию органических тонкопленочных лазеров. В настоящее время требуются новые эффективные источники когерентного излучения, способные излучать одновременно несколько длин волн и не требующих экстремально высоких интенсивностей излучения. Они могут быть востребованы в таких областях, как сенсорика, спектроскопия одиночных молекул, эксперименты в области квантовой оптики, оптогенетике, биомедицине. Для успешной реализации эффективно излучающих тонкопленочных структур требуется обеспечить их хорошие волноводные свойства, предпочтительно используя относительно дешевые материалы и технологии создания таких лазерных структур. В работе изложены принципы создания фотовозбуждаемых тонкопленочных органических волноводных лазеров. Созданы образцы лазеров на основе активного планарного волновода с лазерно-активной средой, состоящей из полиметилакрилата, допированного различными органическими красителями: пиррометен-567, Нильский красный, пиррометен-597, Хромен3. Изучены их генерационные характеристики. Показана возможность реализации органического волноводного лазера с возбуждением от одного источника накачки, генерирующего несколько длин волн одновременно. Ключевые слова: лазер на красителе, планарный волновод, люминесценция, генерация, полиметилметакрилат."

We report the results of studies of the lasing characteristics of an organic solid-state tunable laser with a polymethylmethacrylate matrix doped with Chromene 3, Pyrromethene 567, and Pyrromethene 597 dyes. The features of lasing when using selective and nonselective cavities are described. Tuning of the laser wavelength with a spectral linewidth of 0.018 nm in the range 550 – 628 nm is obtained on three polymer laser-active media emitting in the yellow and red spectral regions.

The paper studies the sensor properties of poly[(9,9-dioctylfluorenyl-2,7-diyl) polymer with terminal dimethylphenyl (ADS129) groups to detect the nitro compound vapor in a laser oscillation mode after the formation of the nitro compound molecular complex. Different solvents are used to obtain ADS129 films.

Nanocomposites based on PMMA and CdSe, CdSe/CdS quantum dots were developed. Quantum dots (QD) of CdSe, CdSe/CdS with sizes from 2.0 nm to 4.0 nm were obtained by deposition in various media. The photoluminescence range for the obtained QDs was from 480 to 628 nm. The results of the study show that the photoluminescent properties of CdSe, CdSe/CdS quantum dots introduced into the PMMA matrix are retained. The resulting nanocomposites can be used to create solid-state laser active media.

The features of spontaneous and stimulated emission of polyfluorenes, polyvinylcarbazole, and low-molecular-weight electron-donor compounds incorporated into various materials are studied in the presence of nitrotoluene vapour. Lasing in planar thin-film waveguides is achieved. The dynamics of the lasing spectra of a thin-film optical chemical sensor is presented. It is shown that the response time of the sensor in the lasing regime is 30 s before the lasing intensity decreases by 50% from the initial level.

Sensor properties poly[9,9-dioctylfluorenyl-2,7-diyl] - end capped with dimethylphenyl - (ADS129) on the nitrotoluens vapor were studied. Sensor properties of the fluorophor dissolved in the different solvents were investigated in the laser mode due to complex formation between fluorophor and nitrotoluene molecules.

In this study, the influence of the annealing conditions on the formation of macrosteps on the anthracene single crystal surface is demonstrated. Under normal conditions (room temperature, atmosphere pressure, and ambient light), the anthracene surface etching proceeds in two stages: formation of macrosteps with widths up to 15 μm and heights up to 200 nm and formation of pinning centers with heights exceeding 300 nm and widths up to 3 μm. Ambient light with wavelengths in the ultraviolet (UV) range causes the formation of pinning centers on the anthracene surface. In this case, no macrosteps are formed during annealing. In the absence of ambient light, terraces with widths larger than 50μm are formed on the anthracene surface without pinning centers.

In this work, the effect of formation of macrosteps under dissolution of the anthracene single crystal surface is shown for the first time. Under standard conditions (room temperature, atmospheric pressure, natural illumination), the etching process of the anthracene single crystal surface can be divided into two stages: formation of macrosteps up to 15 μm in width and 200 nm in height and formation of the step inhibition centers more than 300 nm in height and up to 3 μm in width. The second stage leads to a significant increase in the surface roughness due to the formation of a wave-like relief.

Results of investigation of spectral-luminescent and lasing characteristics of substituted 1,3-oxazoles and 1,3,4-oxadiazoles lasing in the blue-green spectral region are presented. For some compounds, efficiencies of 40 and 38% have been achieved with pump power density of 7 MW/cm 2 . A 34 nm wide tuning range in the blue-green spectral region with lasing line width of 0.012 nm is shown. A series of laser-active compounds with good solubility in methyl methacrylate capable of effectively lasing is determined.

Results of investigation of the spectral-luminescent and lasing characteristics of films based on methacrylates doped with pyrromethene 567 lasing in the yellow-green spectral range are presented. It is shown that incorporation of an additional layer, which improves the waveguide properties of the thin-film structure based on polymethylmethacrylate, increases the energy conversion efficiency and substantially reduces in different degrees the lasing threshold of the examined structures equal to 50–250 kW/cm 2 . In the structure with additional layer, an efficiency of 60% comparable to blocks of solid-state laser-active elements of organic lasers is obtained.

Ink compositions for inkjet printing based on poly(9.9-dioctylfluorene) and its alcohol-soluble analog are created. Current–voltage, brightness–voltage, and spectral characteristics are compared for one- and twolayer polymer structures of organic light-emitting diodes. It is shown that the efficiency of the alcohol-soluble polyfluorene analog is higher compared to poly(9.9-dioctylfluorene), and the possibility of viscosity optimization is higher compared to aromatic chlorinated solvents.

In this paper we demonstrate first, to the best of our knowledge, experimental characteristics of tunable pulsed bulk laser on 3-(diethylamino)-7-imino-7H-[1]benzopyrano[3’,2’:3,4]pyrido[1,2-a]benzimidazol-6-carbonitril (Chromene-3) and 4,4-difluoro-1,3,5,7,8-pentamethyl-2,6-diethyl-4-bora-3a,4a-diaza-s-indacene (PM-567) dyes in polymethyl methacrylate (PMMA) – tuning range and optimal dye concentrations in polymer matrix, from lasing efficiency and tuning range point of view.

The possibility of development of a thin-film 1,4-distirylbenzene–based laser lasing in the blue spectral range in solutions and films is investigated. The stimulated emission of 1,4-distirylbenzene in a polymethylmethacrylate film with transverse pumping by a YAG-Nd 3+ laser is obtained for the threshold power density W = 0.44 MW/cm 2 . It is shown that incorporation of the additional amorphous SiO 2 layer, improving the condition of total internal reflection on the boundary of the active medium, decreases the lasing threshold to 50–70 kW/cm 2 ; in this case, the efficiency of radiation conversion is equal to 20%.

Inkjet ink based on silver nanoparticles with sizes of 11.1 ± 2.4 nm has been developed. Test images are printed on a laboratory inkjet printer, followed by sintering the printed patterns with a diode laser having a wavelength of 453 nm. The structure and electrical properties of the resulting films are studied depending on the parameters of laser sintering. It is found that under optimal conditions, an electrically conductive film with a low resistivity of 12.2 μΩ· cm can be formed.

Spectral-luminescent and lasing characteristics of rhodamine 6G in porous aluminum oxide films anodized under various conditions are investigated. Lasing is obtained without external resonator in the longitudinal scheme under excitation by the second harmonic of Nd 3+ :YAG-laser radiation. The threshold pump power densities are in the range 3.5–15 MW/cm 2 depending on the anodizing conditions. Wherein, the lasing line narrows down from 12 to 5 nm.

Results of investigation of lasing of epoxy polymer compositions with phenalemine 512 and ZnO nanoparticles are given. It is shown that incorporation of ZnO nanoparticles affects the lasing efficiency without reducing the operating lifetime. The material is promising for the development of laser-active media.

Photoluminescent and electroluminescent properties of four new bipolar linear derivatives of divinyl dibenzothiophene sulfone are studied. It is found that amorphous films of solutions, as well as films of the compounds under study in the poly(N-vinylcarbazole) matrix, have a rather high quantum yield of photoluminescence in the blue and blue-green spectrum regions. Bright blue electroluminescence is obtained in the samples with a structure of ITO/PEDOT:PSS/TPD/OC/LiF/Al using vacuum deposition of the compounds under study and in the single-layer ITO/PEDOT:PSS/PVK:OC/LiF/Al structure when applied from the solution with a threshold voltage of 2.5–3.5 V. The influence of a molecule structure on the spectra and quantum yield of fluorescence as well as on the electroluminescent properties of the compounds is shown. Results of quantum-chemical calculations in the context of the density functional theory of the structure and characteristics of main molecular orbitals are presented.