K. W. Cheah

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Benefitting from the flexibility in engineering their optical response, metamaterials have been used to achieve control over the propagation of light to an unprecedented level, leading to highly unconventional and versatile optical functionalities compared with their natural counterparts. Recently, the emerging field of metasurfaces, which consist of a(More)
Organic microcavity light emitting diodes typically exhibit a significant blue shift of the emission wavelength with the viewing angle. In this work, we demonstrate significant reduction of the emission angular dependence of a microcavity device consisting of two organic layers, N,N′-di(naphthalene-1-yl)-N,N′-diphenylbenzidine (NPB) as a hole transport(More)
Optical imaging provides an indispensable way to locate tumors in their early stages with high sensitivity and signal to background ratio. A heptamethine cyanine based fluorophore that emits both single photon near-infrared fluorescence and two-photon deep red fluorescence under physiological conditions was developed. Linear and nonlinear photophysical(More)
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