이명현 교수

We demonstrate a novel on-board chip-to-chip optical interconnect using long-range surface plasmon polariton (LR-SPP) waveguides that feature 2.5-cm-long gold strips embedded in a low loss polymer cladding. A TM-mode vertical-cavity surface-emitting laser (VCSEL) operating at a wavelength of 1.3 microm was butt-coupled into the waveguides in order to excite a fundamental LR-SPP mode and then the transmitted light was received with a photo-diode (PD). The waveguide width is varied in the range of

Polymers are emerging as new alternative materials for optical communication devices. We developed two types of polymer-based devices for optical communications. One type is for ultra high-speed signal processing that uses nonlinear optical (NLO) polymers in such devices as electro -optic (EO) Mach-Zëhnder (MZ) modulators and EO 2×2 switches. The other is for WDM optical communications that use low-loss optical polymers in such devices as 1×2, 2×2, 4-arrayed 2×2 digital optical switches (DOSs) a

Conditioned medium from adipose-derived stem cells (ADSCs) stimulates both collagen synthesis and migration of dermal fibroblasts. However, it is still unknown whether conditioned media from tumor growth factor (TGF)-β1-treated ADSCs (TGF-β1-treated ADSCs-CM) induces increased expression of type I collagen, matrix metalloproteinase-1 (MMP-1), and migration as well as cell cycle regulatory proteins in fibroblasts, compared to non-treated ADSCs-CM. Our data showed that TGF-β1-treated ADSCs-CM prom

A multi-layered nanocomposite thin film was fabricated to increase the density of PbSe quantum dots. It consisted of low-loss polymer layers and multi-stacked PbSe quantum dot layers in series. The solutions of a UV-curable low-loss polymer and PbSe quantum dots were spin-coated layer-by-layer. An arrayed and multi-stacked PbSe quantum dot layer was self-assembled by spin-coating and solvent evaporation. The multi-stacked layers of PbSe quantum dots have a face-centred cubic structure with an av

We evaluate highly fluorinated liquid prepolymers and their UV-cured films for flexible optical waveguide applications. Two liquid prepolymers, 2,3,5,6,2′,3′,5′,6′-octafluoro-4,4′-bis-[2-{2-[1,1-difluoro-2-(2,3,5,6-tetrafluoro-4-vinyl-phenoxy)-ethoxy]-1,1,2,2-tetrafluoro-ethoxy}-2,2-difluoro-ethoxy]-biphenyl (7) and 2,3,5,6,2′,3′,5′,6′-octafluoro-4,4′-bis-[2-(2-{2-[1,1-difluoro-2-(2,3,5,6-tetrafluoro-4-vinyl-phenoxy)-ethoxy]-1,1,2,2-tetrafluoro-ethoxy}-1,1,2,2-tetrafluoro-ethoxy)-2,2-difluoro-et

We demonstrate that a composite surface of microgroove titanium (Ti) with immobilized fibronectin (FN) or bone sialoprotein II (BSP2) promotes osteoblastic differentiation and osteogenic transcription factor expression in human bone marrow-derived mesenchymal stem cells (MSCs). Comparisons made between smooth microgrooves, microgrooves with silanization and microgrooves with matrix protein (FN or BSP2)-immobilization Ti surfaces revealed a significant promotion of in vitro osteogenic activity an

The authors propose and experimentally demonstrate a polarisation-independent all-optical circulating shift register (CSR) based on self-phase modulation of a semiconductor optical amplifier, which is very insensitive to the polarisation of the input pulse train and requires very low switching energy (~176 fJ). An all-optical 91 bit CSR was constructed for an input pulse stream at 2.897 GHz, and a high extinction ratio of 20 dB or more was obtained.

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

Abstract Novel polymer cladding materials were synthesized and their potential for use in optical waveguide devices was investigated. 9‐[2‐(2,3,5,6‐Tetrafluoro‐4‐vinylphenoxy)ethyl]‐9H‐carbazole and 1‐pentafluorophenylpyrrole‐2,5‐dione were used as comonomers for preparing the acrylic cladding copolymers. These showed a low resistivity (≈2 × 10 13 Ω · cm) at room temperature and a low optical loss (−0.6 dB · cm −1 ) at a wavelength of 1.55 µm. The refractive indexes and the glass transition temp

Nonlinear optical (NLO) polymer is emerging as a new alternative material for a wavelength converter in optical fiber communication systems. We designed and synthesized a polyetherimide-based side-chain polymer with a 4-(dialkylamino)-4′(-(styrylsulfonyl)-stilbene chromophore as a new NLO polymer. We designed and fabricated periodically-poled NLO polymer waveguides for the wavelength converter. Difference-frequency generation (DFG) process with a quasi-phase-matching (QPM) scheme was used. For t