Duk-Yong Choi

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Nanophotonic devices enabled by aluminum plasmonics are saliently advantageous in terms of their low cost, outstanding sustainability, and affordable volume production. We report, for the first time, aluminum plasmonics based highly transmissive polarization-independent subtractive color filters, which are fabricated just with single step electron-beam(More)
We demonstrate supercontinuum generation in a highly nonlinear As(2)S(3) chalcogenide planar waveguide which is dispersion engineered to have anomalous dispersion at near-infrared wavelengths. This waveguide is 60 mm long with a cross-section of 2 mum by 870 nm, resulting in a nonlinear parameter of 10 /W/m and a dispersion of +29 ps/nm/km. Using pulses(More)
It has been a long-standing challenge to produce air-stable few- or monolayer samples of phosphorene because thin phosphorene films degrade rapidly in ambient conditions. Here we demonstrate a new highly controllable method for fabricating high quality, air-stable phosphorene films with a designated number of layers ranging from a few down to monolayer. Our(More)
We report first observation of net-gain from an optical parametric amplifier in a planar waveguide. This was achieved in a low-loss As(2)S(3) planar waveguide, with a strong nonlinearity (gamma approximately 10 /W/m) and tailored anomalous dispersion yielding efficient Raman-assisted four-wave mixing at telecom wavelengths. The experiments were in good(More)
We report the first (to our knowledge) demonstration of photonic chip based tunable slow and fast light via stimulated Brillouin scattering. Slow, fast, and negative group velocities were observed in a 7 cm long chalcogenide (As(2)S(3)) rib waveguide with a group index change ranging from ~-44 to +130, which results in a maximum delay of ~23 ns at a(More)
We report the first demonstration of error-free 640 Gbit/s demultiplexing using the Kerr non-linearity of an only 5 cm long chalcogenide glass waveguide chip. Our approach exploits four-wave mixing by the instantaneous nonlinear response of chalcogenide. Excellent performance is achieved with only 2 dB average power penalty and no indication of error-floor.(More)
We demonstrate a high-Q(approximately 125,000) photonic crystal (PhC) cavity formed using a postprocessing optical exposure technique where the refractive index of a photosensitive chalcogenide PhC is modified locally. The evolution of the cavity resonances was monitored in situ during writing using a tapered fiber evanescent coupling system, and the Q of(More)
We report the first demonstration of a photonic chip based dynamically reconfigurable, widely tunable, narrow pass-band, high Q microwave photonic filter (MPF). We exploit stimulated Brillouin scattering (SBS) in a 6.5 cm long chalcogenide (As2S3) photonic chip to demonstrate a MPF that exhibited a high quality factor of ~520 and narrow bandwidth and was(More)