In this work, we demonstrate fully uniform blue fluorescence graphene anode OLEDs, which have an emission area of
10×7 mm<sup>2</sup>. Catalytically grown multilayered graphene films have been used as the anode material. In order to
compensate the current drop, which is due to the graphene’s electrical resistance, we have furnished metal bus lines on
the support. Processing and optical issues involved in graphene anode OLED fabrications are presented. The fabricated
OLEDs with graphene anode showed comparable performances to that of ITO anode OLEDs. Our works shows that
metal bus furnished graphene anode can be extended into large area OLED lighting applications in which flexibility and
transparency is required.
Polymer-based flexible Cu stripe optical waveguides have been developed to configure a board-level optical
interconnection. By embedding Cu stripe in a dual slab waveguide with high refractive-index contrast, the field of the
guided mode is confined more in the two dielectric core layers. Thus, significant reduction of the propagation and
vertical bending loss are expected. The fabricated Cu plasmonic waveguide is flexible enough to be bent down to a
radius of 0.5 mm. The measured optical properties are satisfactory for very short distance board-level optical
interconnection. Based on the experimental results, we concluded that hybrid Cu plasmonic waveguides have a great
potential to be developed as a means of optical signal guiding medium in the optical interconnections.
Chirped Bragg gratings can be utilized in various application regions due to their characteristic spectral and
group delay responses. Chirped Bragg gratings based on the planar waveguide technology can present several
advantages over chirped fiber Bragg gratings. We have proposed and demonstrated that the chirp characteristics
of waveguide Bragg grating (WBG) devices can be tailored by adopting specifically tapered core profiles. On the
ground of our analytical and experimental results, we established the dependence of the modal effective index
on the core width. Using the relationship, we designed and fabricated polymeric WBG devices with precisely
controlled linear chirp parameters. Then, one of the fabricated WBG device was packaged and applied to tunable
dispersion compensation (TDC) for 40-Gbps optical signal transmission. It was ascertained that the optical signal
quality was significantly improved by tuning the operation condition of the packaged TDC module.
Replication technologies have been recommended as an alternative means of high volume manufacturing of the polymer
optical components with low-cost. We demonstrated replication technology as a means of implementing polymer-based
MOEMS. To achieve this, a polymer optical bench with embedded electric circuits was designed to integrate the
functional planar-lightwave-circuit (PLC)-type optical waveguide devices; the designed packaging structures were
realized using a novel fabrication process that incorporated the UV imprint technique. In addition, the detail fabrication
steps of the UV imprint process were investigated. The optical bench has v-grooves for the fiber ribbon and the
alignment pits for opoelectronic interconnection. The plastic mold for imprinting the designed optical bench was made of
UV-transparent perfluorinated polymer material. The designed optical bench was configured on the electric-circuitpatterned
silicon substrate. Flip-chip bonded polymer optical waveguide device showed not only a good electric contact
but also a coupling loss of 0.9 dB at a wavelength of 1.5 ?m. It was concluded that replication technology has versatile
application capabilities in manufacturing next generation optical interconnect systems.
Despite many advantages toward nonlinear optical (NLO) waveguide devices, NLO polymers have not been adopted successfully into practical wavelength converters due to their high absorption losses. Empirical and theoretical understandings about NLO susceptibilities imply the fundamental trade-off between optical absorption and nonlinearity. Our theoretical analysis elucidates the effect of absorption losses on second-harmonic generation, difference-frequency generation, and cascaded wavelength conversion. We compare analytically maximum conversion efficiencies for those NLO processes with several NLO polymers and suggest that the cascaded wavelength conversion is a plausible application of NLO polymers. Furthermore, we found a convincing approach for the development of NLO polymers with the optimum combination of high optical nonlinearity and low material absorption, which leads us to realize efficient polymeric wavelength converters.
The PbSe nanocrystals were synthesized without impurity from lead oleate and Se(TOP) by heating in phenyl ether. The particle size increases the synthesis temperature. The PbSe QD / PPA nanocomposite was made with the synthesized PbSe nanocrystals and the amine-containing PPA polymer by using the ligand exchange method. The PbSe nanocrystals were well dispersed in the PbSe QD / PPA nanocomposite. The PbSe QD / PPA nanocomposite film has the broad PL peak around 1300 nm with FWHM of ~ 170 nm. The time constant in the PbSe QD / PPA nanocomposite film is as slow as ~ 150 ns. We investigated the structures of the developed PbSe QD / PPA nanocomposite film as well as their optical properties, and then suggested their photonic applications.
A 16-arrayed polymeric optical modulator is fabricated using an electro-optic (EO) polymer with a large EO coefficient and good thermal stability. The 16-arrayed modulator has lumped type electrodes with a response time of less than one nanosecond. The 16-arrayed modulator has good uniform modulation characteristics between the individual modulators. The deviation of half-wave voltages is 0.2 V and that of insertion losses about 1 dB. Crosstalks range from -28 to -36dB and extinction ratios are more than 21 dB.
Recently, we developed a wavelength converter, a 16-arrayed electro-optic (EO) Mach-Zehnder (MZ) modulator, polarization adjustable and athermal arrayed waveguide gratings (AWGs), and a wavelength channel selector by using all polymers. We designed and fabricated periodically poled nonlinear optical (NLO) polymer waveguides for the wavelength converter. Difference-frequency generation (DFG) process with a quasi-phase-matching (QPM) scheme was used. An all polymer-based wavelength channel selector composed of 16-channel EO polymer modulator array between two polymer AWGs is proposed and fabricated using chip-to-chip bonding of the three optical polymeric waveguide devices. For this, the 16-arrayed polymeric optical modulator and AWGs are respectively fabricated using EO and low-loss optical polymers. For these two-typed devices, we have synthesized new side chain NLO polymers and used low-loss optical polymers, designed and developed by ZenPhotonics, Inc. The developed these photonic devices were discussed in details from materials to packaging.