Yung-Jr Hung

  • Citations Per Year
Learn More
Tapered silicon photonic crystals (PhCs) with smooth sidewalls are realized using a novel single-step deep reactive ion etching. The PhCs can significantly reduce the surface reflection over the wavelength range between the ultra-violet and near-infrared regions. From the measurements using a spectrophotometer and an angle-variable spectroscopic(More)
Silicon antireflection is realized with vertical-aligned SiNWs by using improved metal-induced etching technique. The spectral responses of the transmission, reflection, and absorption characteristics for the SiNWs of different lengths are investigated. In order to realize short SiNWs to provide sufficiently low reflection, a post chemical etching process(More)
A fabrication strategy is proposed to enable precise coverage of as-grown carbon nanotube (CNT) mats atop vertically aligned silicon nanowire (VA-SiNW) bundles in order to realize a uniform bundle array of CNT-SiNW heterojunctions over a large sample area. No obvious electrical degradation of as-fabricated SiNWs is observed according to the measured(More)
A simple and efficient approach for fabricating silicon nanopillar arrays with a high aspect ratio and controllable sidewall profiles has been developed by using holographic lithography and a novel single-step deep reactive ion etching. During the etching process, scalloping of the sidewalls can be avoided while reserving the high mask selectivity and high(More)
We have experimentally investigated single-port injection-triggered switching in a new class of semiconductor ring lasers with integrated gain, phase and passive waveguide sections as a building-block for all-optical signal processing such as high-speed analog-to-digital conversion. ©2009 Optical Society of America OCIS codes: (250.3140) Integrated(More)
A complete investigation of holographic photonic crystal structures has been conducted. From both theoretical and experimental results, profiles of resultant patterns under different process conditions can be estimated and controlled. The use of antireflection layers is crucial for realizing submicron photonic crystals with good uniformity over a large(More)
We demonstrate for the first time, continuous frequency tuning MHz using symmetric phase tuning regions in an InGaAsP/InP 18 GHz passively mode-locked ring laser. Frequency tuning is achieved through current injection into passive waveguides, via the free-carrier plasma effect, which is enhanced by the concurrent increase in cavity losses from free-carrier(More)
Compact flattened InP/InGaAsP multiquantum-well (MQW) resonators based on etched beam splitters (EBS) with 300to 800-nm gaps and circumferences of 30–300 m are demonstrated. Comparison of the EBS coupler reflection and transmission to 3-D finite-difference time-domain (FDTD) simulations shows good agreement in the wider EBS gap devices. Lasing is observed(More)
This work proposes a tunable reflective guided-mode resonant (GMR) filter that incorporates a 90° twisted nematic liquid crystal (TNLC). The GMR grating acts as an optical resonator that reflects strongly at the resonance wavelength and as an alignment layer for LC. The 90° TNLC functions as an achromic polarization rotator that alters the polarization of(More)