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.
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.
We propose a polymeric variable optical attenuator based on long range surface plasmon polaritons (LRSPPs) along a thin metal stripe embedded in polymers. The device is operated by controlling radiation loss of the LRSPP mode resulting from the temperature gradient of the polymer cladding caused by a heater. For guiding LRSPPs and efficient coupling of single mode fibers, gold stripes with 20-nm thickness, 4-μm width and 1-cm length are utilized. To obtain long physical lifetime, the heater is formed on the top of the polymer cladding with a 200-nm Au film which is about ten times thicker than the thin metal waveguide. The fabricated device is characterized at a wavelength of 1.55 μm, exhibiting high attenuation of less than 30 dB with the operating power of 100 mW. The fiber-to-fiber total insertion loss of 6.1 dB is achieved when using single mode fibers.
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.
Photonic band gap interaction between surface plasmon (SP) and dielectric gratings is calculated by rigorous coupled wave analysis (RCWA). Results from the RCWA show that the reflectance goes down near to 0%, and the diffraction efficiency increases above 50% even though the modulation depth of the grating layer is less than 100nm. If the grating vector is twice of the wave vector of SP, on the other hand, the reflectance surprisingly increases up to 90% even though the resonance condition of the SP is satisfied. This photonic band gap effect at the SP resonance can be completely analyzed by the RCWA, and verified by experiment.