Edwin Yue-Bun Pun

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Here, we investigate the spin-induced manipulation of orbitals using metasurfaces constructed from geometric phase elements. By carrying the spin effects to the orbital angular momentum, we show experimentally the transverse angular splitting between the two spins in the reciprocal space with metasurface, as a direct observation of the optical spin Hall(More)
Broadband emissions at around 1.20 and 1.46 μm wavelengths from thulium (Tm(3+))-doped tellurite glasses were observed under 465 nm wavelength excitation. The 1.20 μm emission originates from the Tm(3+): (1)G(4)-->(3)H(4) transition, and the associated stimulated peak emission cross-section is calculated to be 0.47 × 10(-20) cm(2). Population inversion(More)
We report a systematic study on the dependence of nanowire evanescent wave coupling efficiency on wavelength, cross angle, and core diameter. An 800 nm diameter silica taper was used for light launching. Three poly(trimethylene terephthalate) nanowires with 640 nm, 790 nm, and 950 nm diameters were used for light transmission. Five wavelengths (visible,(More)
Superbroadband near-infrared (NIR) emission covering 1250 to 1680 nm wavelength has been obtained in praseodymium (Pr(3+)) singly doped bismuth gallate glasses. The emission originates from the (1)G(4)→(3)H(5) and (1)D(2)→(1)G(4) transitions at 1330 and 1490 nm wavelengths, respectively, and is due to the extremely low phonon energy (∼690 cm(-1)) and the(More)
Superbroadband emission from 1.0 to 1.7 μm wavelength was observed in thulium-bismuth (Tm-Bi) codoped sodium-germanium-gallate (NGG) glasses under 793 nm excitation. Efficient energy transfer process from Bi to Tm ions, with value as high as 67.7%, was achieved which is beneficial in achieving flat broadband lineshape. The large stimulated emission(More)
For the first time, a new-type flat focal field arrayed waveguide grating (AWG) demultiplexer, with the focal signals of all wavelengths of operation focusing along a straight line, is designed based on the aberration theory and fabricated based on a newly developed negative tone epoxy Novolak resin (ENR) polymer using electron-beam direct writing. A(More)
A cluster model is proposed for study of the effects of the number of ions per cluster on the performance of a heavily erbium-doped fiber laser. The results indicate that both the threshold pump power and the unstable-operation region of the fiber laser increase with increasing numbers of ions per cluster.
A novel and simple Sm(3+)-doped-polymer/Ag/ SiO(2) trilayer structure was fabricated to investigate the impact of surface plasmon polaritons (SPPs) on the emission quantum efficiency of the dipole emitter Sm(3+). Photoluminescence (PL) enhancement factors for samples with different Ag thicknesses (30-70 nm) were found to be different when the thickness of(More)
We report a near-stoichiometric Ti:Zr:LiNbO(3) strip waveguide fabricated from a congruent substrate with a technological process in the following sequence: Zr<sup>4+</sup>-diffusion-doping, diffusion of 8-μm-wide, 100-nm-thick Ti strips, and post-Li-rich vapor transport equilibration. We show that Zr(4+)-doping has little effect on the LiNbO(3) refractive(More)
Intense near-infrared emission located at 1.23 μm wavelength originating from the erbium (Er(3+)):(4)S3/2→(4)I11/2 transition is observed in Er(3+)-doped fluorotellurite glasses. This emission is mainly contributed by the relatively low phonon energy of the fluorotellurite glass host (~776 cm(-1)). Judd-Ofelt analysis indicates a strong asymmetry and(More)