Browsing by Author "Sio, Kuan-Un"

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Multi-Functional Light Emitter Based on Band-Edge Modes Near Gamma-Point in Honeycomb Photonic Crystal
(2011-06-15)
Lee, Po-Tsung
;
Lu, Tsan-Wen
;
Sio, Kuan-Un
;
光電工程學系
;
Department of Photonics
In this report, we demonstrate multi-functional light emitter based on band-edge modes near Gamma-point in a two-dimensional honeycomb photonic crystal slab. Different band-edge modes near Gamma-point are identified, including the monopole (Gamma(2)), dipole (Gamma(4,5)) and quadrupole (Gamma(6,7)) modes. The monopole and quadrupole modes lasing are observed with high side-mode suppression-ratio of 35 dB and high index sensitivity of 375 nm per refractive index unit, which shows their potential in optical micro-laser and index sensor applications. Over five-fold photoluminescence enhancement with broad band-width of 100 nm from the dipole mode is also observed at room temperature, which shows the advantage of honeycomb lattice structure for designing high brightness light emitting diodes.
Optical sensing of square lattice photonic crystal point-shifted nanocavity for protein adsorption detection
(2010-05-24)
Lu, Tsan-Wen
;
Lin, Pin-Tso
;
Sio, Kuan-Un
;
Lee, Po-Tsung
;
光電工程學系
We propose a point-shifted D(0) nanocavity formed by locally modulating four central air holes in square lattice photonic crystal for optical sensing application. Three defect modes in this nanocavity, including monopole, whispering-gallery, and dipole modes, are identified in experiments. We also apply a chemical treatment on InGaAsP surface to form a 1-octadecanethiol linking monolayer, which enables the following protein adsorption. In experiments, the wavelength shifts of lasing modes in the D(0) nanocavity due to the protein adsorption are observed and agree with the simulation results. This can be a practical tool for label-free molecule detection in biomedical researches. (C) 2010 American Institute of Physics. [doi:10.1063/1.3436550]
Square Lattice Photonic Crystal Point-Shifted D(0) Nanocavity with Lowest-Order Whispering-Gallery Mode
(2010)
Lu, Tsan-Wen
;
Lin, Pin-Tso
;
Sio, Kuan-Un
;
Lee, Po-Tsung
;
光電工程學系
We propose a square photonic crystal point-shifted nanocavity, which sustains an ultra-small lowest-order whispering-gallery mode. Lasing actions with low threshold of 160 mu W and changed polarization due to a nearby nano-particle are observed. (C)2010 Optical Society of America
Square lattice photonic crystal point-shifted nanocavity with lowest-order whispering-gallery mode
(2010-02-01)
Lu, Tsan-Wen
;
Lin, Pin-Tso
;
Sio, Kuan-Un
;
Lee, Po-Tsung
;
光電工程學系
We propose a point-shifted nanocavity based on square lattice photonic crystal, which sustains a lowest-order whispering-gallery (WG) mode. In simulation, the optimized WG mode (quality (Q) factor similar to 14,000) in point-shifted nanocavity can be with smaller mode volume (similar to 5.5(lambda/2n)(3)) but larger nano-post tolerance than those in single-defect cavity design. From well-fabricated device, single WG mode lasing with measured Q factor of 4,100 and low threshold of 160 mu W is obtained. Besides, we also observe the changed polarization of WG mode due to modal symmetry breaking caused by the presence of a nearby dielectric nano-particle, which would be useful in sensing molecule binding or attaching for bio-chemical applications. (C) 2010 Optical Society of America