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We investigate the design of binary grating structures, e.g. resonance waveguide filters (RWFs), with subwavelength feature sizes, taking the temperature dependence of different material parameters into account. Our final goal is to demonstrate devices with athermal operation. We design the binary grating structures to be made in polymer substrates, such as(More)
Gallium selenide (GaSe) is a layered semiconductor and a well-known nonlinear optical crystal. The discovery of graphene has created a new vast research field focusing on two-dimensional materials. We report on the nonlinear optical properties of few-layer GaSe using multiphoton microscopy. Both second- and third-harmonic generation from few-layer GaSe(More)
UNLABELLED We fabricated self-assembled silver nanoisland films using a recently developed technique based on out-diffusion of silver from an ion-exchanged glass substrate in reducing atmosphere. We demonstrate that the position of the surface plasmon resonance of the films depends on the conditions of the film growth. The resonance can be gradually shifted(More)
Surface enhanced Raman scattering (SERS) fiber probes have enormous potential in optical sensing applications. However, their widespread use has been hindered by two major obstacles: the difficulty of fabricating the required silver nanostructures on optical fibers and the tarnishing of silver, rapidly degrading their sensing properties. Here we propose a(More)
There have been many papers reporting visible luminescence and light emission at 1.54 micron, at room temperature, from porous silicon (Psi) and from Erbium doped Psi, respectively. These results have stimulated a great deal of excitement, because they suggest the possibility of a silicon based optoelectronics technology. In this paper, in order to generate(More)
We review the significance of optical thin films by Atomic Layer Deposition (ALD) method to fabricate nanophotonic devices and structures. ALD is a versatile technique to deposit functional coatings on reactive surfaces with conformal growth of compound materials, precise thickness control capable of angstrom resolution, and coverage of high aspect ratio(More)
Carbon is the most well-known black material in the history of man. Throughout the centuries, carbon has been used as a black material for paintings, camouflage, and optics. Although, the techniques to make other black surfaces have evolved and become more sophisticated with time, carbon still remains one of the best black materials. Another well-known(More)
Name of the doctoral dissertation Silver nanoparticles embedded in glass by ion exchange method for biosensor applications Abstract This thesis focuses on the fabrication of silver nanoparticles (Ag NPs) embedded in glasses and their applications for surface enhanced Raman spectroscopy (SERS). Firstly, Ag NPs are produced in microscope slides and high iron(More)
In this paper, a design for a 1 ˆ 4 optical power splitter based on the multimode interference (MMI) coupler in a silicon (Si)–gallium nitride (GaN) slot waveguide structure is presented—to our knowledge, for the first time. Si and GaN were found as suitable materials for the slot waveguide structure. Numerical optimizations were carried out on the device(More)