This PDF file contains the front matter associated with SPIE Proceedings Volume 7599, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.

The electron transporting molecule tris(8-hydroxyquinoline) aluminum (Alq₃) was introduced into a photorefractive composite in a low density to study the effects of electron traps on the performance. Compared to a control sample, Alq₃ samples exhibited higher dielectric strength, over-modulation at reduced voltage, and increased writing speed. Transient measurements indicated grating revelation via decay of a competing grating. The dynamics are consistent with a bipolar charge transport model. Overall, Alq₃ improves the sensitivity, trapping, and breakdown voltage without significant losses in absorption or phase stability.

Hybrid particles from insoluble luminescent π-conjugated polymers were formed through a miniemulsion approach. The color characteristics of the PL for the particles could be tuned by exploiting the Förster resonance energy transfer between the polymers within a particle, while suppressing energy transfer between particles, and exhibited 1931 CIE x,y-color coordinates that ranged from 0.153, 0.071 to 0.267, 0.559 with corresponding dominant wavelengths of 466 nm to 536 nm with an excitation energy at a wavelength of 389 nm.

The functionalization of colloidal surfaces has been an area of scientific research for several decades. With the emergence of click reactions, particularly the copper(I) catalyzed version of Huisgen 1,3-dipolar cycloaddition between azides and alkynes, new pathways to functionalize the particle surface in aqueous environments have opened for researchers to explore. In colloidal systems synthesized by free radical polymerization with monomers containing azides or alkynes, networked polymers are produced due to the bifunctionality of both monomers. The primary means of characterizing the success of these reactions due to the rigidity of the crosslinked particle is the use of a chromophore as the "clicked' material or titrations of a weak acid that has been "clicked'. Herein, the piecewise process of building a core-shell particle is described that avoids the unwanted crosslinking of an alkyne containing monomer. Due to the control of the piecewise fabrication, the polymer shell can removed with a favorable solvent pre- or post-functionalization with an azide-functionalized anthracene molecule.

In the present work, the hyper-branched (HB) polymer is utilized as a host material to efficiently incorporate the nonlinear optical chromophore. The HB polymer and toluene diisocyanate (2, 4-TDI) formed 3-D networks, and the typical FTC or CF3-Ph-FTC chromophores were introduced to investigate the electro-optic activity (r₃₃). At the same time, poling behavior of NLO chromophores in the traditional poly methyl methacrylate (PMMA) and Poly MMA-MOI side-chain polymers were also included in this work for comparison. For FTC doped composites, the r₃₃ reached over 80 pm/V in 3-D network matrix, while the value of r₃₃ maximized at about 45 pm/V in traditional PMMA host and 70 pm/V in side-chain polymers. In addition, the measurement of poling process, poling efficiency, and thermal stability for the real application were also investigated.

The reliability of high speed polymer electro-optic (EO) modulators is the most critical milestone for the use of these materials in commercial applications. We present recent thermal stability data at material and device level that proves the stability at 85 °C for 25 years of GigOptix' polymer modulators. Fundamentally, the reliability of the device materials lays the foundation for stable final devices, thus the EO materials properties was monitored from batch to batch after synthesis and during wafer fabrication. Key parameters at chip level were analyzed to show the performance distribution on a 6" wafer. Thermal study performed at chip level fitted using Jonscher model was used to determine the isothermal aging stability of EO coefficient for 25 years and the EO materials' activation energy. M3 EO material shows <10 % change in EO coefficient while operating at 85 °C for 25 years.

Several high-performance polymeric electro-optic modulators have been demonstrated in the last decade. Most of them have been elaborated using specific high-performance electro-optic polymers designed for their exceptional electro-optic response and their thermal stability. In this paper we report the high performance of electro-optic modulators made of a commercial side-chain electro-optic copolymer DR1-PMMA as the active core material and of a passive epoxy polymer NOA73 as cladding material. The electro-optic polymer used in these modulators is a Disperse Red 1- poly-methylmethacrylate (DR1-MMA) side-chain copolymer with relative molar concentrations of DR1-substituted (resp. MMA unsubstituted) groups equal to 30% (resp. 70%). We have designed, elaborated and tested phase modulator and pushpull Mach-Zehnder modulators in order to optimize their figure of merit V_πL. A push-pull Mach-Zehnder modulator with 2 cm-long electrodes and an inter-electrode distance of 8.8 μm displays a half-wave voltage of 2.6 V at 1550 nm, corresponding to a figure of merit of 5.2 V.cm. This result was obtained with a moderate poling electric field of 75 V/μm applied to the core of the modulator waveguide. We report here the best figure of merit which has never been observed in a modulator realized with a commercial side-chain electro-optic polymer.

We demonstrate electro-optic modulation in hybrid organic-crystal/silicon photonic waveguides. The organic material is the newly developed organic crystal OH1 with very high electro-optic figures of merit, n³r = 530 pm/V at 1319 nm, and the processing possibilities considerably improved compared to previous high-nonlinearity organic crystals. We have developed an epitaxial-like solution growth of OH1 on various substrates and fabricated electro-optic modulators with electro-optic functionality either directly in OH1 wire waveguides or in OH1 active cladding of silicon wire waveguides. OH1-based waveguides offer a great potential for high-bandwidth, sub-1-V half-wave voltage, hybrid organic/silicon electro-optic modulators with high electro-optic activity and stability.

In this paper, we present novel designs for the realization of organic-inorganic hybrid material systems and develop concepts and designs for silicon-organic hybrid ultrafast RF Photonic Devices. The designs presented combine, crystalline electro-optic materials, conventional crystalline materials, and amorphous polymers. Numerical simulation results as well as fabrication results are also included.

We present optical, photoluminescent (PL), and photoconductive properties of functionalized anthradithiophene (ADT) and benzothiophene (BTBTB) derivatives and their composites. Solution-deposited ADT films exhibit charge carrier mobilities of over 1.5 cm²/Vs, high PL quantum yields, and high photoconductivity at room temperature. We show molecular arrangement and intermolecular interactions significantly contribute to the (opto)electronic properties of thin films of these pi-stacked materials. In addition, these properties can be effectively manipulated through the addition of guest molecules to a host material. In particular, exciton and charge carrier dynamics can be varied using a competition between photoinduced charge and energy transfer in a guest-host system. To better understand these processes at a molecular level, we apply single-molecule fluorescence spectroscopy (SMFS) to probe the effects of intermolecular interactions on the molecular properties. Specifically, we demonstrate that ADT molecules exhibit high enough quantum yields and photostability to be imaged on a single-molecule level at room temperature. Moreover, we show that stability of single ADT molecules immobilized in a solid-state matrix are comparable to those of the best fluorophores utilized in SMFS.

Novel fabrication technique of organic solid state waveguide dye laser has been developed for easy fabrication and surface integration. Polymeric waveguides fabrication based on dispensing and drawing scheme can control a refractive index with 0.001 resolution and can stack multiple-layer just in a limited area. It can realize more complicated laser system in comparison with our previous technique. New proposed DFB laser with Quasi-Mode-Coupled were also demonstrated in improve performance.

We investigated the effects of trans-stilbene unit in compensating birefringence in the random copolymerization method and the anisotropic molecule dopant method. In the random copolymerization method, trans-stilbene methacrylate (TSMA) containing the trans-stilbene unit in the side chain was polymerized with methyl methacrylate (MMA) in solution polymerization to compensate the photoelastic birefringence and the orientational birefringence of poly(methyl methacrylate) (PMMA). In the anisotropic molecule dopant method, trans-stilbene was added to PMMA. In the both methods, the photoelastic birefringence and the orientational birefringence shifted from the negative side to the positive side with an increase in the concentration of trans-stilbene unit. 0.8 mol% of TSMA almost eliminated the photoelastic birefringence. Also, we demonstrated that poly(MMA/TSMA) exhibited no orientational birefringence with 1.9 mol% of TSMA. 2.0 mol% of trans-stilbene almost eliminated the photoelastic birefringence of PMMA. Similarly, we demonstrated compensating orientational birefringence with 2.0 mol% of trans-stilbene. Based on the results, the effects of trans-stilbene unit in compensation of orientational birefringence are almost the same in the two methods. However, in compensation of photoelastic birefringence, the trans-stilbene unit had 2.5 times higher effect in the random copolymerization method than that in the anisotropic molecule dopant method. Photoelastic birefringence is caused in elastic deformation below T_g, in which the side chains are mainly orientated while the polymer main chains are scarcely orientated. Therefore, we concluded that addition of trans-stilbene unit to the side chain enhanced the effect for compensating photoelastic birefringence.

We compare the experimental absolute two-photon absorption (2PA) cross sections and spectra of various organic molecules with those obtained from the few (two or three) essential states model, assuming certain parameter values that are either previously calculated theoretically or measured. We study conditions under which the two- or three-level models are applicable for quantitative description of 2PA, and estimate the corresponding maximum realistic attainable peak 2PA cross sections and spectral widths. Based on our observations we formulate the steps required to increase the intensity and broaden the spectral coverage of instantaneous 2PA by optimizing intrinsic molecular parameters such as transition dipole moments, permanent dipole moments and excited states energies.

We measure and quantitatively analyze two-photon absorption (2PA) spectra and cross sections in a series of Oxazine molecules with varying chemical structures. We compare values of the permanent dipole moment difference (Δμ) obtained by three different methods: (a) 2PA cross sections using two-level approximation; (b) Stark spectroscopy, and (c) solvatochromic shifts. The first two methods give coinciding Δμ values, thus justifying two-level approximation, while solvatochromic shifts measurements yield systematically higher Δμ values. Possible reasons for such a discrepancy are discussed.

The preparation is described of a novel highly emissive ytterbium complex with a proposed unusual structure obtained by reaction of tricyanovinylbenzene (TCNVB) with bis(indenyl)ytterbium(II) in THF. The reaction occurs under extremely mild conditions, the tetraphenyltetracyanoporphyrazine macrocycle being assembled in high yield from TCNVB building-blocks by Yb³⁺-template synthesis. The analytical, spectral and electrochemical investigations of the obtained ytterbium complex indicate its existence in the form of a binuclear adduct with Yb(TCNVB)3 species in which a one doubly reduced TCNVB molecule bridges two Yb³⁺ cations. The formation of a disordered polynuclear coordination polymer network including a macrocyclic structure and metal cations bridged through the nitrile nitrogen atoms is proposed. The complex is readily soluble and is compatible with a variety of polymeric matrices giving doped polymeric glasses and films which are highly luminescent in the biologically relevant optical window covering the visible and near infrared range (640-1000 nm). In addition, doped polymeric glasses and films highly emissive at the telecommunication wavelength (1540 nm) including the novel ytterbium complex and originally not luminescent erbium chelate in an equimolar ratio have been obtained. The compound is found to be an extraordinarily strong sensitizer of near-IR Er³⁺ emission. Use of the Yb complex as a fluorescent marker for biomedical in vitro investigations has been demonstrated.

Optical and photostability measurements have been made on nonlinear optical films containing amorphous polycarbonate and an organic chromophore that has a high 2nd order nonlinear optical figure of merit. We show that the decrease in the photodegradation quantum efficiency with increasing optical intensity can be modelled in terms of oxygen depletion by oxygen-mediated chomophore photodegradation. The addition of a known singlet oxygen quencher, beta carotene, leads to a 1100% decrease in the photodegradation quantum efficiency.

Nonlinear transmission upon the formation of an optically induced photonic band gap (PBG) is demonstrated by using periodic layers of optical polymers doped with highly nonlinear transition metal oxides. The refractive indices of the alternating layers are designed to be close and no PBG is formed at low power densities. Under high power illumination, the index difference becomes large because of the high optical nonlinearities of the transition metal oxides. Consequently, nonlinear transmission is accomplished with the formation and the broadening of the PBG. Compared to typical optical limiters based on a PBG approach, our devices provide a large dynamic range and a broad operation wavelength range. The experiments on a nonlinear Bragg mirror consisting of only 4 pairs of PVA:Co₃O₄-PVK, each with a layer thickness of 85 nm, show a linear transmittance of greater than 50% throughout the visible, and nonlinear transmission for a 10 ns laser pulse at 523 nm with a threshold of 30 mJ/cm² and a minimum transmission of about 10%. The minimum transmission reduces to 5% for a 12-pair device. Improving the uniformity of each layer and adding more pairs can result in even lower transmission at high intensities. The threshold can be further reduced through precise design and control of the thickness of each layer. The device and material approach is promising for applications such as protection for broadband detectors and human eyes.

Nonlinear transmission is found to be significantly enhanced by introducing heavy metal atoms on the periphery of macrocycle porphyrin complexes via rhenium selenide clusters that are coordinated to four pyridyl groups. Experiments on 5, 10, 15, 20-tetra(4-pyridyl) porphyrin (H₂TPyP), CuTPyP, [Re₆(μ₃-Se)₈(PEt₃)₅]₄(H₂TPyP)(SbF₆)₈ (abbreviated as P5H₂TPyP), and [Re₆(μ₃-Se)₈(PEt₃)₅]₄Cu(TPyP)(SbF₆)₈ (abbreviated as CuP5TPyP) using 10 ns laser pulses at 523 nm show that, in contrast to CuTPyP and P5H₂TPyP, which are saturable absorbers at a low fluence of 1-100 mJ/cm² and become nonlinear absorbers with a threshold larger than 1000 mJ/cm² at high fluence, CuP5TPyP exhibits an excellent nonlinear transmission performance with a threshold as low as 20 mJ/cm². A bulky rhenium selenide cluster was coordinated to pyridyl groups in tetrapyridyl porphyrin. The modified copper (II) porphyrin complex CuP5TPyP has strong nonlinear absorption at 523 nm and synergistic interaction between CuTPyP and P5H₂TPyP is one of possible mechanisms.

We present a new approach to modeling of homogeneous line shape in two-photon absorption (2PA) spectra of chromophores with large permanent dipole moment difference between the ground- and excited electronic states using numerical solution of stochastic two-level density matrix equation of motion. Good agreement with experimental 2PA line shapes is obtained for S1←S0 transition of Styryl 9M, which allows us to estimate that the permanent dipole moment difference varies in this chromophore within the S1←S0 band in the range, Δμ = 12 - 25 D.

In this work, a drop-on-demand piezoelectric ink-jet system has been employed to fabricate disposable photodiodes as the detectors on the integrated lab-on-chip lasers. J-aggregated films of a cyanine dye, NK-1952 doped into a conductive polymer, poly(3,4-ethylenedioxythiophene) poly(styrene sulfonate) (PEDOT:PSS) on the indium tin oxide (ITO) substrate have made by the ink-jet method, respectively. With the thin Al layer on the top of cyanine dye films as the cathode, while ITO substrate as the anode, the photodiodes have been demonstrated to be wavelength sensitive under the excitation of a tunable pico-second laser, which corresponds to the characteristic red-shifted, sharp and narrow J-aggregate absorption peak of each cyanine dye employed. The influence of ink-jet fabrication parameters, presence of metal ions and pH value of dye solutions on the J-aggregate formation and also the wavelength sensitivity of the photodiodes have been systematically investigated and the mechanisms involved have been discussed. It is found that by optimizing the ink-jet fabrication parameters such as UV exposure dose amount, and substrate temperature, or by introducing ions such as K⁺, Na⁺, or H⁺, the wavelength resolution of the ink-jet printed photodiodes can be improved significantly, and wavelength resolution of less than 0.1nm may be expected.

We demonstrate optofluidic evanescent dye lasers based on two types of solid distributed feedback (DFB) grating cavities- the first order linear DFB gratings which gives in-plane laser emitting and second order circular DFB gratings which gives surface laser emitting. For both of them, the laser mode is confined within the waveguide and experience optical gain via evanescent wave coupling with the dye solution. Benefitting from the solid waveguide cores, stable and narrow linewidth laser output were observed with a large tolerance of fluid refractive indices, which prove the feasibility of integrating fluid evanescent gain dye laser into passive waveguide circuit.

The effect of self-assembled monolayers on the molecular stack of discotic liquid crystals has been studied. The self-assembled monolayers, which consist of functional groups on the terminal of the silane molecules, were formed by attaching themselves on a solid surface, and the surface energies of substrates were found to be varied greatly. On the substrates modified by the 3-aminopropyltriethoxysilane, which possess higher surface free energy, discotic molecules tend to assemble with disk-face-on anchoring; whereas discotic molecules tend to assemble with disk-edge-on anchoring when stacking on the substrate surface modified by the octadecyltrichlorosilane, which possess lower surface free energy. The initial observation also revealed the capability to imprint specific patterns of discotic molecular orientation on the substrate surfaces via silane modifications.

Block copolymers have drawn increasing attention for fabricating functional nanomaterials due to their properties of self-assembly. In particular, photonic crystals hold promise for multiple optical applications. We prepared 1D photonic crystals with polystyrene-b-poly(2-vinyl pyridine) (PS-b-P2VP) lamellar films which is hydrophobic block-hydrophilic polyelectrolyte block polymer of 57 kg /mol-b-57 kg/mol. The lamellar stacks, which are alternating layers of hydrophilic and hydrophobic moiety of PS-b-P2VP, are obtained by exposing the spin coated film under chloroform vapor. The band gaps of the lamellar films interestingly varied after immersion into the quaternizing solvents containing 5wt% of iodomethane solubilized in n-hexane. We demonstrate about the influence of UV light on those photonic gel films. To study of different properties of films, UV-visible absorption spectra were measured as a different UV irradiation time at swollen films with distilled water. The UV-visible maximum absorption spectra shifted by UV irradiation time. Dependent on the time of UV irradiations, we can change the photonic band gap.

Photosensitive polyimide containing 2-methoxy cinnamate was synthesized for photo-alignment layer of liquid crystals (LCs). 2-Methoxy cinnamic acid was confirmed photo-sensitive material by linearly polarized UV light. We studied that effect of polarized UV light on rubbed polyimide film. Anchoring energy of liquid crystal with aligning surface was measured. Irradiation of depolarized UV light on rubbed Polyimide film suppressed effective anchoring energy. Linearly polarized UV light on rubbed polyimide film controlled anchoring energy effectively. Polyimide film containing 2-methoxy cinnamate can control the photo-alignment layer easily due to its photo-sensitivity.

We have proposed a novel encapsulation method with simple process in comparison with conventional encapsulation technique. Here, the encapsulation film of silicon dioxide is steady for external environment because this can be designed to cover the emitting organic material from air. Silicon dioxide of 220 nm was deposited by plasma enhanced chemical vapor deposition and etched by reactive ion etching system. Then, Alq₃ was used as a material to emitting layer in the green (organic light emitting device) OLED and TPD in the hole transportation layer was used for the harmonious transportation of hole. Luminance was measured with 40 hour intervals at the air-exposed condition. After 400, 1,000, 1,600, and 2,000 hours, luminance of green OLED were 7,366, 7,200, 6,210, and 5,100 cd/m², respectively. Luminance of green OLED doesn't decrease until 2,000 hours. As a results, proposed encapsulation technique can increase the life time of green OLED.

Organic electro-optic (EO) materials are the materials of choice for high speed optical modulators with modulation frequencies greater than 100 GHz. This is due to the large EO effects observed and a low material dispersion of the dielectric constant resulting in a very small velocity mismatch between the optical and electrical waves. However, the implementation of organic materials into real devices has been hindered by several factors such as an insufficient long-term thermal and photochemical stability of the widely investigated poled polymers or the lack of available structuring techniques for the inherently superior organic EO crystalline materials. Here we report on the realization of integrated organic EO single-crystalline Mach-Zehnder modulators by a recently developed melt based channel growth technique. The main fabrication concept is to grow the organic EO singlecrystals from the melt directly in pre-structured and electroded waveguide channels, which were obtained by standard optical lithographic techniques and wafer bonding. By this method single crystal structure details with a size below 30 nm have been achieved and the growth of single-crystalline Mach-Zehnder modulators has been successfully demonstrated, where we have chosen DAT2 (2-(3-(2-(4-dimethylaminophenyl)vinyl)-5,5- dimethylcyclohex-2-enylidene)malononitrile) as EO material. The half-wave voltage × length product determined in the DAT2 based Mach-Zehnder modulators has been found to be 78 ± 2 Vcm for TE-modes and 60 ±1 Vcm for TM-modes at a wavelength of 1.55 μm. The accuracy and reproducibility of the process allowed also for the realization of the first EO single-crystalline microring resonator in an organic material.

Herein we present our results from the picosecond and nanosecond nonlinear optical studies of two novel phthalocyanines {[(SO₃Na)₄CuPc] and [(SO3Na)4NiPc]} using the Z-scan technique. Open aperture Z-scan data revealed that the picosecond nonlinear absorption was dominated by three-photon absorption while in the nanosecond domain reverse saturable absorption prevailed. Closed aperture data with nanosecond pulses indicated strong thermal, negative nonlinearity while picosecond excitation demonstrated positive nonlinearity. The nonlinearity in CuPc was higher than in NiPc in both the time domains. The nonlinear coefficients extracted from the fits to experimental data were large compared to some of the recently reported works on similar molecules.

We present our results on the characterization of ultrafast excited state dynamics of two phthalocyanines in thin film form studied using femtosecond pump-probe technique. One was a symmetric Zinc phthalocyanine (SPc) while the other was an unsymmetrical Zinc phthalocyanine (USPc). The femtosecond (fs) pulses at 800 nm were characterized using a single shot autocorrelator. The pump probe measurements were carried out with 590/610 nm pulses emanating from an optical parametric amplifier. SPc demonstrated an excited lifetime of ~30 ps while the ASPc exhibited ~60 ps lifetime. The potential applications of these molecules are discussed briefly.

The intrinsic deterioration in device performance of polymeric single layer OLEDs that were doped with a fluorescent emitter was studied. The specific focus was on the role that thermal aging, at sub-glass transition temperatures of the polymeric layer, has on the phase separation of the active layer. This was accomplished by the rational design of an oxadiazole-containing methylacrylate monomer that was energetically similar to the technologically important electron- transporting small molecule 2-biphenyl-4-yl-5-(4-tert-butylphenyl)-1,3,4- oxadiazole (tBu-PBD). This monomer was copolymerized with a carbazole containing hole-transporting monomer 2-(9H-carbazol-9-yl)ethyl 2-methylacrylate (CE) and the resulting copolymer was utilized as the active layer with coumarin 6. With coumarin 6, the devices exhibited a stable mean luminance of ca. 400 cd/m² with thermal aging at temperatures ranging from 23 °C to 130 °C, while a comparable poly(9-vinyl-9H-carbazole)/tBu-PBD blend device exhibited a drop from an initial mean luminance of 2500 cd/m² to 1.6 cd/m². The reduction in luminance and luminance efficiency for the blend system was attributed to phase separation in the blend.