Thin films of gold (Au) have found use in various optoelectronic applications due to their unique optical properties. Depending on the film morphology, the optical response can display localized surface plasmon resonance related to isolated metal clusters and a Drude-like response emerging from a connected metal network. Therefore, Au films, especially those with nearly percolated morphology display a very broad optical response that can be drastically varied by control of the fabrication conditions or post-deposition treatments. In this study, we investigate the optical and morphological changes observed in thin Au films subjected to thermal annealing as potential building units for optical-based thermal sensors. Three different film morphologies (island film, nearly percolated film, and compact film) are obtained by controlling the amount of deposited metal. The evolution of morphological properties of these three types of films upon thermal annealing follows different mechanisms, resulting in enhanced optical changes in different spectral regions. In addition, we show that the incorporation of nearly percolated films in multilayer interference coatings can significantly boost their potential as irreversible temperature sensors. Overall, we show that the unique morphological changes induced by annealing combined with interference effects hold great promise for thermal sensing.
Quantum networks have been shown to connect users with full-mesh topologies without trusted nodes. We present advancements on our scalable polarisation entanglement-based quantum network testbed, which has the ability to perform protocols beyond simple quantum key distribution. Our approach utilises wavelength multiplexing, which is ideal for quantum networks across local metropolitan areas due to the ease of connecting additional users to the network without increasing the resource requirements per user. We show a 10 user fully connected quantum network with metropolitan scale deployed fibre links, demonstrating polarisation stability and the ability to generate secret keys over a period of 10.8 days with a network wide average-effective secret key rate of 3.38 bps.
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.