황의헌 교수

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> A detailed 3-D finite-difference time-domain analysis of photonic crystal double-heterostructure bound state resonances is presented along with supporting experimental results. The connection between different photonic crystal waveguide bands and the associated photonic crystal double-heterostructure bound states is made, and mode profiles are presented. We analyze the quality factors using the PadÉ

As an attempt to collect more in-plane emission power out of wavelength size two-dimensional photonic crystal defect lasers, edge-emitting photonic crystal double-heterostructure quantum well membrane lasers were fabricated by shortening the number of cladding periods on one side. 120μW peak output power was collected from the facet of the single mode laser at room temperature. Laser efficiencies were analyzed and agree very well with three-dimensional finite-difference time-domain modeling.

In order to reduce the optical absorption loss, an array of double-heterostructure photonic crystal microcavity lasers was fabricated in which much of the photonic crystal mirror region was disordered by quantum well intermixing. In characterizing these devices, we obtained more than a factor of two increase in slope efficiencies and more than 20% reduction in threshold pump powers compared to devices that were not intermixed.

We demonstrate a very high quality (Q) factor wavelength filter based on a buried heterostructure (BH) microresonator platform technology. A 200-μm-radius BH ring resonator is integrated with a semiconductor optical amplifier (SOA) using offset quantum wells for loss-cancellation. The resonator is operated near critical coupling at I/sub SOA/=29 mA, which yields a coupling-limited Q of 2.0×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> w

Double-Heterostructure photonic crystal microcavity lasers were fabricated in which much of the photonic crystal mirror region was disordered by quantum well intermixing. An increased slope efficiency and a reduced threshold pump power was obtained.

We propose a tunable laser incorporating a cleavage-free wavelength selective reflector (WSR) formed by buried heterostructure (BH) microring resonators. Utilizing the proposed tunable reflector, a compact, 100-GHz-channel-spaced tunable laser is demonstrated.

Record-high edge-emitted peak power was collected from L3 and finite-waveguide two-dimensional photonic crystal nanocavity quantum well membrane lasers at room temperature under single-mode operations. Peak power levels of 230 microW and 540 microW were collected from L3 and finite-waveguide edge-emitters, and their quantum differential efficiencies are 11% and 27%, respectively, limited by their collection efficiencies in free space.

InAs/InGaAsP quantum dots (QD) grown on InP substrates show strong photoluminescence (PL) signals, with peaks from 1.4 to 1.6 µm at room temperature. Time-resolved PL measurements reveal that carrier lifetimes are the same across the entire PL band at low temperature, as well as at room temperature. This is strong evidence that the PL originates from the inhomogeneously broadened states of well-isolated QDs even at room temperature. These good characteristics, with the availability of additional

An array of double-heterostructure photonic crystal QW membrane lasers was fabricated in which number of cladding periods was varied. 60 μW peak output power was collected from the facet of one device by a bare fiber.

Record room temperature single-mode edge-emitted peak power was collected from L3 and finite-waveguide photonic crystal nanocavity quantum well membrane lasers. Peak power levels of 230 and 540μW were collected from L3 and finite-waveguide edge-emitters, respectively.

The properties of active semiconductor microresonators as compact universal components (optoelectronic transistors) that enable them to serve multiple functions in photonic integrated circuits are described. The challenges and progress in their development are described.

Multiple bound states in photonic crystal double heterostructure resonant cavities are analyzed using the three-dimensional finite-difference time-domain method. Quality factors and mode profiles are presented. A method for mode discrimination is discussed.

A comprehensive review of the fabrication process, fundamental properties and functionalities and device applications of heterogeneously integrated two-dimensional (2D) materials is provided. An extensive library of atomic 2D materials with selectable material properties exists and it is rapidly expanding, with which it is possible to construct hybrid or heterostructures that display novel properties with unique functionalities. Such heterostructures adding a degree of freedom to carriers in the