Search

Molybdenum oxide films were deposited using modulated pulse power magnetron sputtering (MPPMS) from a molybdenum target in a reactive environment where the flow rate of oxygen was varied from 0 sccm to 2.00 sccm. By varying the amount of reactive oxygen available during deposition, the composition of the films ranged from metallic Mo to fully stoichiometric MoO3, when the molybdenum target became poisoned, due to the formation of a dielectric surface oxide coating. Film compositions were verified using high energy resolution x-ray photoelectron spectroscopy. Target poisoning occurred at an oxygen flow rate of 1.25 sccm and reversed when the flow rate decreased to about 1.00 sccm. MoO3 films deposited via MPPMS had densities of 3.8 g cm−3, 81% of the density of crystalline α-MoO3 as determined by x-ray reflectivity (XRR). In addition, XRR and atomic force microscopy data showed sub-nanometer surface roughness values. From spectroscopic ellipsometry, the measured refractive index of the MoO3 films at 589 nm was 1.97 with extinction coefficient values

Titanium nitride (TiN x ) thin films were grown by radio-frequency (RF) magnetron sputter deposition by varying the nitrogen content in the reactive gas mixture over a wide range. The effect of nitrogen gas flow rate on the surface and interface morphology, chemical composition and optical properties of TiN thin films was studied employing atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Analysis of the optical properties probed with SE has shown that films deposited at low (0–5 sccm) nitrogen flow rates have the highest absorption at energies 2 flow rate, remaining consistent thereafter. SEM cross-sectional imaging analysis indicates the dense, columnar structure for the films grown at lower nitrogen flow rates. XPS analysis of atomic composition and the chemical states indicate that the atomic composition remained nearly constant while the chemical states varied significantly among the samples as a function of N 2 flow rate. XPS analyses confirm the presence of TiN x , TiO 2 and TiO x N y . These process–property relationships derived could be useful for defining and expanding the range of optical and electronic applications of titanium nitrides and (oxy)nitrides.

We report on the universal fabrication of Janus microparticles from a wide variety of organic and inorganic components. The Janus particle fabrication described in this study details the synthesis of the highly cross-linked polymer nanocoatings on top of the partially embedded particles via plasma enhanced chemical vapor deposition. Here we conducted the plasma enhanced polymerization of different organic functionalized, reactive, responsive, and biomolecular materials ranging from acrylic compounds to organometallic molecules and aminoacids all directly on silica and titania microspheres, while using a masking technique to ensure that only a controlled fraction of the total particle surface area will be covered. This facile, fast, and scalable selected polymerization approach allows for single-face polymerization, generating organic−inorganic Janus particles which are robust and can be further converted into a variety of interesting mesoscale structures. Half-fluorescent, half-metal-decorated, and half-s...

A novel method for the facile fabrication of conformal, ultrathin, and uniform synthetic amino acid coatings on a variety of practical surfaces by plasma-enhanced chemical vapor deposition is introduced. Tyrosine, which is utilized as an agent to reduce gold nanoparticles from solution, is sublimed into the plasma field and directly deposited on a variety of substrates to form a homogeneous, conformal, and robust polyamino acid coating in a one-step, solvent-free process. This approach is applicable to many practical surfaces and allows surface-induced biometallization while avoiding multiple wet-chemistry treatments that can damage many soft materials. Moreover, by placing a mask over the substrate during deposition, the tyrosine coating can be micropatterned. Upon its exposure to a solution of gold chloride, a network of gold nanoparticles forms on the surface, replicating the initial micropattern. This method of templated biometallization is adaptable to a variety of practical inorganic and organic substrates, such as silicon, glass, nitrocellulose, polystyrene, polydimethylsiloxane, polytetrafluoroethylene, polyethylene, and woven silk fibers. No special pretreatment is necessary, and the technique results in a rapid, conformal amino acid coating that can be utilized for further biometallization.

We report subnanosecond photoluminescence (PL) decay dynamics of dendron decorated poly(phenylene vinylenes) (PPVs) in solutions and as neat films. Previous PL studies revealed that two conformations of the polymer, with distinct luminescence quantum yields and PL, are responsible for the photophysics of these polymers. These conformations are characteristic of isolated and aggregated chains. From the decay dynamics, energy transfer between the two species is evident and repopulation of exciton states occurs in aggregated regions of the sample.

We compare the photoluminescence (PL) of poly-p-phenyl-enevinylene (PPV) to that of one of its soluble derivatives, poly (2-methoxy, 5-(21-ethylhexoxy)-p-phenylenevinylene) (MEH-PPV). We show that excimers due to π-orbital overlap of adjacent polymer backbones are formed in MEH-PPV in high quantum yield. They do not emit light at room temperature, potentially explaining the reduction of PL yield in MEH-PPV films relative to solution. The herringbone packing of polymer chains in PPV prevents π-π stacking, but low PL yields are observed anyway. We conclude that polymer design to inhibit interchain registration is a questionable strategy to increase luminescence yields. The low PL yield in PPV is ascribed to bound polaron pair formation and preliminary data suggest that these may also form upon photoexcitation of MEH-PPV films.

We study the photophysics of poly-phenylenevinylene (PPV) polymers with large dendritic sidegroups under both isolated chain and aggregated chain conditions. Aggregation causes a substantial reduction in photoluminescence (PL) quantum yield but that decrease is ameliorated by the attachment of an additional generation of dendron to the PPV backbone. Three-dimensional separation of chromophores can be achieved with these sidegroups and the formation of nearly non-emissive interchain excitations leads to a factor of four enhancements in solid-state PL.

We report measurements of photoluminescence from films of a soluble phenylenevinylene polymer that has prospective importance as the emissive material in light-emitting diodes. We show unambiguously that there is long-lived emission in this material due to excimers and estimate that the quantum yield for excimer formation is as high as 50%. Since excimers in this polymer largely decay nonradiatively at ambient temperature, their prominence serves to drastically reduce the possible efficiency of electroluminescent conjugated polymer devices.

ZnO and Ag thin films were deposited using pulsed laser deposition and magnetron sputtering, respectively. Aperiodic ZnO/Ag multilayer stacks exhibited high transmittance in the visible range while blocking UV and IR radition.

The frequency and magnitude of the applied voltage pulses were varied under constant oxygen/argon flow rates to obtain alternating layers of molybdenum trioxide (MoO3) and metallic molybdenum (Mo) using a single Mo target.

One-dimensional photonic band gap (PBG) materials created from holographic polymer dispersed liquid crystals (H-PDLCs) provide enhanced light localization in an organic electro-optic device. Distributed feedback within the reflection notch of a H-PDLC grating narrowed the bandwidth of pyrromethene 597 fluorescence from 56 to 8.4nm at a lasing threshold of 0.12mJcm−2, compared to 2.6mJcm−2 required to observe amplified spontaneous emission in a nonstructured, but comparable floodlit (PDLC) sample. Application of an electric field (10–40V∕μm) continuously decreased the diffraction efficiency of the grating and the commensurate dynamic lasing intensity thus demonstrating electrically modulated gain from an optically pumped, all-organic PBG.

A holographic polymer-dispersed liquid-crystal (H-PDLC) grating film was employed as an angle-dependent and narrow spectral-band feedback control element for two-photon pumped lasing in a dye solution, 4-[N-(2-hydroxyethyl)-N-(methyl)amino phenyl]-4′-(6-hydroxyhexyl sulfonyl) stilbene (APSS) in dimethyl sulphoxide. The grating film contained about 80 layers of liquid-crystal domains periodically dispersed in an ∼15 μm thick polymer film, featuring a maximum reflectance of 75% at 561 nm position with an ∼9 nm spectral bandwidth. The output lasing wavelength could be tuned from 561.5 to 548.5 nm and the lasing bandwidth changed from 5 to 3 nm when the incidence angle on the grating film varied from 0° to 22°. The overall lasing efficiency was measured to be 10%.

In this paper we report the use of plasma-enhanced chemical vapor deposition (PECVD) for the simultaneous deposition and copolymerization of an amino acid with other organic and inorganic monomers. We investigate the fundamental effects of plasma-enhanced copolymerization on different material chemistries in stable ultrathin coatings of mixed composition with an amino acid component. This study serves to determine the feasibility of a direct, facile method for integrating biocompatible/active materials into robust polymerized coatings with the ability to plasma copolymerize a biological molecule (l-tyrosine) with different synthetic materials in a dry, one-step process to form ultrathin coatings of mixed composition. This process may lead to a method of interfacing biologic systems with synthetic materials as a way to enhance the biomaterial–tissue interface and preserve biological activity within composite films.

We compare two designs of metallodielectric stacks (MDS) based on Ag/GaP and Au/GaP, and calculate their superresolving bandwidths. The super-resolving bandwidth of the Ag/GaP design is (520nm-560nm), while that of Au/GaP is (630nm-660nm). We evaluate these two designs in their ability to resolve two 20nm wide apertures separated by a center-to-center distance of 80nm. We also compare two numerical techniques used to study these systems, namely the transfer matrix method (TMM) and the finite element method (FEM). The TMM is simpler than more numerically demanding FEM technique but FEM is more robust for determining super-resolution in most cases. Finally we discuss the practical limitations of our super-resolving imaging devices in resolving objects that are much smaller than the incident wavelength.

We report on the conformal synthesis of ultrathin films from the amino acid histidine on flat silicon substrates and 3D periodic polymer structures via plasma enhanced chemical vapor deposition. We demonstrate the efficient utilization of this functional amino acid nanocoating for the formation of individual titania nanoparticles with dimensions from 2 to 15 nm depending upon reduction conditions. The titania nanoparticles were grown directly on histidine-functionalized planar and 3D polymer substrates by a wet-chemistry method that showed uniform surface coverage that reached approximately 75%. This approach demonstrates the potential for modifying the optical properties of periodic porous polymeric structures via direct conformal growth of titania nanoparticles.

Plasma enhanced chemical vapor deposition (PECVD) of biologically active films is investigated for the fabrication of bio-inspired chemical vapor sensors, due to the ability to fabricate thin films with unique surface chemistries.

TiOxNyCzthin films plasma polymerized at room temperature experienced significant decreases in film thickness and increases in refractive index with time during air exposure. Correlation of optical and structural changes provided insight into densification mechanisms.

A sensitive interferometric method is employed to quantify the deformation of silicon substrates coated with thin plasma-polymerized acrylonitrile film deposited at room temperature. This provides insight into the structural variation of plasma polymerized films.

Electrically switched distributed-feedback (DFB) lasing action is presented in a Pyrromethene 580 lasing dye-doped holographic polymer dispersed liquid crystal (H-PDLC) transmission grating structure. This design, when compared with the previously utilized H-PDLC reflection grating structure, has the advantage of a greatly enlarged gain length (10 mm) and a low concentration of liquid crystal (20%) while maintaining sufficient refractive index modulation. The experimental results demonstrate that the emitted laser bandwidth (~5 nm) can be obtained with a pump energy threshold of ~0.3 mJ at three different wavelengths, 561 nm, 569 nm and 592 nm, corresponding to three different grating spacings. The near- and far-field measurements have shown a high directionality of the lasing output. The lasing can be electrically switched off by an applied field of 30V/mum. The temporal, spectral, and output/input properties of the laser output are also presented.

Holographic photopolymerization, such as used to form holographic polymer dispersed liquid crystals (HPDLCs), has the advantage of combining the desirable processing properties of polymers with a periodic distribution of an electrically tunable medium (LC). Herein we describe laser oscillations resulting from distributed feedback in fieldmodulated, 2-D H-PDLC photonic crystals. Compared to results of lasing from pyrromethene 597 in 1-D H-PDLCs, the linewidth of the laser action decreases by at least a factor of four and the lasing wavelength is electrically tunable over 5 nm. The 2-D H-PDLCs consist of LC columns within a polymer matrix that were created by interference of four writing beams on the sample cell. Two configurations were studied; one comprising a reflection grating orthogonal to a transmission grating (in-plane) and the other from two orthogonal transmission gratings (out-of-plane). Given that the lattice spacing was the same for both samples, the lasing wavelengths were similar; however the polarization dependence on lasing threshold varied by a factor of three for the in-plane configuration and electrical switching resulted in bimodal lasing. The out-of-plane geometry showed no polarization dependence on lasing threshold and the lasing blue-shifted with applied electric field.

Holographic polymerization (H-P) has been used to fabricate polymer-dispersed liquid crystals, block copolymers and pattern inert nanoparticles. In this article, one-dimensional grating structures of Norland resin and a polymer blend were achieved using the H-P technique. A reflection grating structure known as a Bragg reflector (BR) was fabricated. The hierarchical structure and morphology of the BR were studied using synchrotron X-ray, polarized light microscopy and transmission electron microscopy. The structure of the BR containing a polymer blend displayed lamellae structures formed with periodicity of 200 nm. Polycaprolactone and Poly(L-lactide) crystals were found to be confined in ~ 60 nm thick layers in the BR. The polymer chains tended to orient themselves parallel to the grating when the two polymers where blended together. The phase separation and structure of the polymer blend inside the H-P grating could be of great interest for multifunctional optical sensors or devices.

A comprehensive photophysical study of the linear and nonlinear absorption properties has been carried out on two series of two-photon absorbing dyes to gain insight into how structure-property relationships influence observed nonlinear absorption. The materials studied consist of an electron accepting benzothiazole group connected to an electron donating diphenylamine via a fluorene bridging group. Two series differ from each other by the addition of one phenyl group and for each series one-arm (dipolar, AF240 and AF270), two-arm (quadrupolar, AF287 and AF295), and three-arm (octupolar, AF350 and AF380) versions were studied. Overall the AF240 series exhibits higher intrinsic two-photon absorption (TPA) cross-sections than the AF270 series as well as enhanced nanosecond nonlinear absorption, with an increase with number of branches. The enhanced nanosecond nonlinearity is understood by taking into account the contribution from the singlet and triplet excited states and was verified by a two-photon assisted excited-state absorption model that satisfactorily predicts the nonlinear absorption of the chromophores.

Oxide materials of desired stoichiometry are challenging to make in small quantities. Nanostructured thin films of multiple oxide materials were obtained by using pulsed laser deposition and multiple independent targets consisting of Si, BaTiO3, and B. Programmable stoichiometry of nanostructured thin films was achieved by synchronizing a 248-nm krypton fluoride excimer laser at an energy of 300 mJ/pulse, a galvanometer mirror system, and the three independent target materials with a background pressure of oxygen. Island growth occurred on a per pulse basis; some 500 pulses are required to deposit 1 nm of material. The number of pulses on each target was programmed with a high degree of precision. Trends in material properties were systematically identified by varying the stoichiometry of multiple nanostructured thin films and comparing the resulting properties measured using in situ spectroscopic ellipsometry, capacitance measurements including relative permittivity and loss, and energy dispersive spectroscopy (EDS). Films were deposited ∼150 to 907 nm thickness, and in situ ellipsometry data were modeled to calculate thickness n and k. A representative atomic force microscopy measurement was also collected. EDS, ellipsometry, and capacitance measurements were all performed on each of the samples, with one sample having a calculated permittivity greater than 20,000 at 1 kHz.

Interference lithography of polymer dispersed liquid crystals allows rapid, facile fabrication of complex polymeric photonic structures that have an inherent electro-optic component for agile structures. The polymerization mechanism (step-growth or chain growth) strongly influences the morphology of the LC droplet and distribution within the polymer matrix. Using a multi-functional acrylate monomer that undergoes chain growth polymerization leads to asymmetrical LC droplets of random size and distribution, in contrast to the step-growth mechanism of thiol-ene formation where LC droplets form with a nearly uniform size distribution and spherical shape. Thiol-ene holographic polymer dispersed liquid crystals (H-PDLCs) diffraction structures have narrower bandwidth and less baseline scatter than the acrylatebased H-PDLCs. Furthermore, distributed feedback lasers constructed from thiolene-based H-PDLC lasers show marked improvement in the optical and electro-optical properties as evinced by the factor of two decrease in switching voltage and the reduction of lasing threshold from 0.17 mJ cm-2 to 0.07 mJ cm-2. These differences in optical and electro-optic properties directly correlate with the difference in microscale morphology of the H-PDLCs giving insight to the importance of microscale structure on macroscale phenomenon.

Multifunctional acrylate formulations containing nematic liquid crystals have been shown to form holographic polymer dispersed liquid crystal gratings (H-PDLCs) easily using ultra-violet AND/OR visible photoinitiators. Laser wavelengths of 364, 476, 488, 514, 532 and 647 nm have been used for the fabrication of the gratings. Recently, the use of a thiol-ene based monomer system has been shown to overcome some of the adverse effects like post polymerization, voltage creep, and non-uniform shrinkage incurred when using highly functional acrylate monomers. However, Bragg reflection gratings have only been demonstrated utilizing ultra-violet (UV) (363.8 nm Argon ion) photopolymerization. Using UV irradiation and single prism geometry limits the upper end of the reflection notch wavelength. In this work, we report on new visible photoinitiator systems developed for the formation of reflective H-PDLCs using thiol-ene monomers. Using these new photoinitiator systems, reflection notches have been routinely written from the visible to the near infrared (IR) regions. The visible photoinitiator systems included the photoinitiator and radical generator titanocene organo-metallic complex (commercially known as Irgacure 784 (Ciba-Geigy), Rhodamine 6G, Pyrromethene, and a radical generating organic peroxide as coinitiator. Reflection gratings were written using laser wavelengths 442, 488, and 532 nm with diffraction efficiencies (DEs) above 70%. Angle tuning allowed for gratings with reflection notches in the near IR (900-1500 nm) to be written using these initiator systems. Rhodamine 6G was found to be more efficient than the other two initiators. We discuss here this new chemistry, the morphology, and electro-optical properties of the reflection gratings.

Holographic polymerization of liquid crystal containing photopolymerizable resins enables one-step, rapid formation of multi-phase structures that exhibit partial photonic band gaps. These holographic polymer dispersed liquid crystals (H-PDLCs) provide a versatile platform for diffractive optical elements because the structures are not limited by multi-phase equilibrium but are controlled by the interference of multiple lasers at discrete angles. Incorporation of laser dyes into H-PDLCs form 1-D and 2-D optically pumped distributed feedback lasers. Linewidths as narrow as 1.8 nm are observed with laser thresholds below 1 mJ/cm 2 in 2-D columnar structures compared to 9 nm and 25 mJ/cm2 exhibited by 1-D H-PDLC Bragg stack lasers. In the 2-D lattices the energy of the laser action can be tuned within the gain spectrum of the lasing medium by an applied electric field.

Holographic polymerization of liquid crystal containing photopolymerizable resins enables one-step, rapid formation of multi-phase structures that exhibit partial photonic band gaps. These holographic polymer dispersed liquid crystals (H-PDLCs) provide a versatile platform for diffractive optical elements because the structures are not limited by multi-phase equilibrium but are controlled by the interference of multiple lasers at discrete angles. Incorporation of laser dyes into H-PDLCs form 1-D and 2-D optically pumped distributed feedback lasers. Linewidths as narrow as 1.8 nm are observed with laser thresholds below 1 mJ/cm/sub 2/ in 2-D columnar structures compared to 9 nm and 25 mJ/cm/sub 2/ exhibited by 1-D H-PDLC Bragg stack lasers. In the 2-D lattices the energy of the laser action can be tuned within the gain spectrum of the lasing medium by an applied electric field.

Holography offers a versatile, rapid and volume scalable approach for making large area, multi-dimensional, organic PBGs; however, the small refractive index contrast of organics prevents formation of a complete band-gap. The introduction of inorganic nanoparticles to the structure provides a possible solution. In contrast to the multiple steps (exposure, development and infiltration) necessitated by lithographic-based holography (e.g. photoresists), holographic photopolymerization of monomer-nanoparticle suspensions enables one-step fabrication of multidimensional organic-inorganic photonic band gap (PBG) structures with high refractive index contrast. The PBGs are formed by segregation of semiconductor nanocrystals during polymerization of the polymer network. Addition of CdSe/ZnS polymerization of the highly cross-linked polymer network. Addition of CdSe/ZnS quantum dots or ZnO nanocrystals to the H-PDLCs formulation results in phase segregation of the nanoparticles into the liquid crystal rich lamellae, producing photonic structures with high diffraction efficiencies that may be modulated by application of an external electric field.

This article [J. Nanophoton.. 8, (1 ), 083890 ( Feb 5 , 2014)] mistakenly appeared in the Special Section on Metamaterials and Photonic Nanostructures. It was republished in the Special Section on Nanostructured Thin Films VI with a corrected CID on 10 February 2014. The updated citation is shown below

The supercontinuum (SC) generated by pumping in anomalous dispersion is sensitive to the input pulse fluctuations and pump laser’s shot noises and does not possess a single-pulse waveform, so the incident pulse becomes a noise-like train of spikes. A simple method of creating pulsed lasers with either pulse-maintaining ultrabroad SC or specially shaped pulse waveforms can be implemented using all-normal-dispersion microstructured optical fibers (ANDi-MOFs). An ANDi-MOF with a simple topology and dispersion profile maximum at 800 nm was designed using the effective index method. Its properties and suitability were characterized via numerical simulation of femtosecond parabolic pulse formation and generation of an octave-spanning pulse-maintaining SC using a generalized propagation equation. The designed ANDi-MOF is suitable for resolving both problems and allows some detuning of the pulse’s wavelength around 800 nm. However, a better choice for SC generation is pumping at or near the wavelength where the third-order dispersion becomes zero. This configuration benefits from the absence of pulse break-up under large pulse energies, which appears otherwise. The fiber can provide a low-cost method for developing supercontinuum sources and a solution to the problems of parabolic waveform formation to meet the needs of optical signal processing and pulse amplification and compression.

Pulsed laser deposition is an energetic deposition technique in which thin films are deposited when a laser pulse at 248-nm wavelength strikes a target and material is subsequently deposited onto a substrate with ideally the same stoichiometry. By synchronizing a high-speed mirror system with the pulsing of the laser, and using two separate targets, thin films having tunable stoichiometry have been deposited. Depositions were performed in a high vacuum envi- ronment to obtain as much kinetic energy as possible during growth. Typically, some 150 pulses at 300 mJ∕pulse were required to deposit 1 nm. Island growth must occur on a per pulse basis since over 100 pulses are required to deposit a 1 nm film thickness. Films were deposited to ∼100-nm thickness, and in situ ellipsometry data were modeled to calculate thickness, n and k. X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and atomic force microscopy (AFM) were all performed on each of the films. XPS demonstrated change in film composition with change in laser pulse ratio; ellipsometry displayed thickness from the model generated as well as the optical properties from 370 to 1690 nm. AFM thickness measurements were in agree- ment with independently modeled ellipsometry thickness values. © 2014 Society of Photo-Optical Instrumentation Engineers (SPIE) (DOI: 10.1117/1.JNP.8.083999)

We demonstrate an approach toward the design of starburst C60-keto-DPAF assembly by applying a starburst macromolecular configuration with C60 as the core center, which is encapsulated by multiple bulky groups leading to the increase of intermolecular separation and aggregation barrier. Molecular compositions of the resulting C60(>DPAF-C9)2 triad and C60(>DPAF-C9)4 pentads were clearly confirmed by MALDI-MS (positive ion) detection of protonated molecular mass ions. Both C60(>DPAF-C9)22 and C60(>DPAF-C9)4 (structural isomers, 3a and 3b) exhibited nonlinear optical transmittance reduction responses in the femtosecond (fs) region with a lower transmittance value for the latter at the high laser power above 80 GW cm−2. This was attributed to the larger fs 2PA cross-section values of 3a and 3b than that of 2 at the same concentration and, apparently, correlated to a higher number of DPAF-C9 subunits in the structure of 3. As the concentration was decreased to 10−4 M, a clear monotonous increase of the σ2 value change (Δσ2) from 13.9, 33.2, to 48.1 and 68.2 × 10−48 cm4 s photon−1 molecule−1 (or 6820 GM for the latter) for the structural variation from the monoadduct 1, bisadduct 2, to tetraadducts 3b and 3a, respectively, was observed. We interpreted the concentration-dependent phenomenon as being due to the high tendency of fullerene-DPAF chromophores to form nanoscale aggregates at concentrations above 10−3 M. We also proposed that starburst structures, as exemplified by C60(>DPAF-C9)4, in a multipolar arrangement resembling encapsulation of C60 by DPAF-C9 pendants, provide a useful means to increase the degree of molecular dispersion and maintain high nonlinear optical efficiency.

Random laser action is demonstrated in organic–inorganic, disordered hybrid materials consisting of ZnO semiconductor nanoparticles dispersed in an optically inert polymer matrix. The ZnO particles provide both the gain and the strong scattering power that leads to light trapping due to multiple elastic scattering, whereas the polymer matrix offers ease of material fabrication and processability in view of potential applications. Excitation of the nanohybrids by a laser pulse with duration shorter than the ZnO photoluminescence lifetime leads to a dramatic increase in the emitted light intensity accompanied by a significant spectral and temporal narrowing above a certain threshold of the excitation energy density. Critical laser and material parameters that influence the observed laser-like emission behavior are investigated in a series of nanocomposites.

Analysis of plasma polymerized TiOxCyNzfilms annealed in the temperature range of 300-700oC, revealed different mechanisms responsible for film densification below 300oC and the formation of TiO2crystalline phases at temperatures over 500oC.