The future of photonic devices involves harnessing non-linear effects, for applications such as frequency upconversion and down-conversion, optical switching, and emission control. To effectively do this, the optical properties of designed material systems are needed. Hyperbolic metamaterials that use both conductors and dielectrics have been shown to have enhanced non-linear properties near the topological transition point. Creating that topological transition point in a layered hyperbolic metamaterial offers a way to control the non-linear properties without a complicated 3D design. Layered 1D metamaterials still have a large enough design space to achieve various non-linear effects across a large frequency range and have a relative ease of fabrication. For this research, ITO was chosen as the conductor, which has advantages due to its ready availability and CMOS compatibility. The chosen dielectric, SiO2, is also easily available. The non-linear properties of the hyperbolic metamaterials were modeled with an efficient Matlab code, and the results show the capability of controlling the non-linear properties and optimizing for many different possible applications.
The future of photonic devices involves harnessing non-linear effects, for applications such as frequency upconversion and down-conversion, optical switching, and emission control. To effectively do this, the optical properties of designed material systems are needed. Metamaterials can be fabricated in a layered form to operate in many wavelength bands, and they exhibit strong non-linear effects. To make the layered metamaterial, alternating layers of metal and dielectric were used. Samples were fabricated using physical vapor deposition for the material system ITO-SiO2, with varying layer thicknesses for each sample. First, the linear properties of the samples were measured using variable angle spectral ellipsometry, and then the non-linear properties were measured using the Z-scan technique. The linear results show a good agreement with effective medium theory, which signifies that the metamaterials are suited for computer-aided design. Also, the non-linear results show strong non-linear properties, of n2 = 1 ∗ 1014 cm2/W, and β = 2 ∗ 1010 cm/W, which is larger than many natural materials. This demonstrates the potential for use in non-linear applications.
The future of optical devices involves manipulation of nanoscale structure. Thus, novel samples that incorporate both photonic crystal (PC) structure and metamaterial properties, known as PC metamaterials, are proposed. First, metamaterials with no PC structure are fabricated as nanorod or nanohelical structures and characterized to extract their optical constants. Then, a computational model for the metamaterial within a PC structure was developed to calculate the photonic bandgap (PBG). These results show that a large PBG with the desired directionality can be achieved with these PC metamaterials.
The BRDF describes optical scatter off realistic surfaces. The microfacet BRDF model assumes geometric optics but is computationally simple compared to wave optics models. In this work, MERL BRDF data is fitted to the original Cook-Torrance microfacet model, and a modified Cook-Torrance model using the polarization factor in place of the mathematically problematic cross section conversion and geometric attenuation terms. The results provide experimental evidence that this modified Cook-Torrance model leads to improved fits, particularly for large incident and scattered angles. These results are expected to lead to more accurate BRDF modeling for remote sensing.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.