Increasingly fast and reliable communications support the operation of industries, the Internet of things, and consumer electronics, underpinning the exchange of information and knowledge. Most services rely on optical interconnects that provide high-capacity, low-cost, low-power consumption interconnects between data centers, high-performance computing, and the Internet. According to the Cisco report, the network traffic, including the Internet, has increased to 40 Zettabytes of data in 2020. To put the numbers in perspective, the total data generated from the beginning of humanity until 2003 is 0.5% of a Zettabyte. Furthermore, the ever-increasing data traffic accounted for 12% of total global emissions in 2020. As a result, it is crucial to develop efficient networks with higher capacity and reduced power consumption. This project will contribute to more efficient phase shifters, impacting data/telecom and quantum systems. This research will exploit the properties of indium arsenide quantum dots, including 1. the temperature resilience to demonstrate a phase shifter for cryogenic photonic interconnects used in high-performance computing (quantum): indium arsenide quantum dot's temperature resilience will outperform competing developments employing quantum wells. 2. the resilience to threading dislocation, and material stress of quantum dots, will be exploited to integrate the phase shifter over silicon to bring more efficient phase shifters and modulators to the silicon photonic platform. They will outperform current III-V quantum well monolithic integration approaches due to their stress resilience. Due to silicon's weak modulating effects, it is impossible to produce efficient phase shifters. On the other hand, quantum dots exhibit stronger effects than silicon, increasing bandwidth and reducing power consumption. This development will impact the commercial optical interconnects using silicon-based photonic integrated circuits (PICs) and current networks relying on them. Additionally, this work will contribute to the development of cryogenic optical interconnects. This project partners with 1. Carleton University (Canada), 2. Colorado State University (United States), 3. Télécom ParisTech (France), 4. University College Cork and Tyndall National Institute (Ireland), and 5. VTT Technical Research Centre (Finland) to develop the technology.

Delivery of audio has become increasingly complex: originally in single channel (mono) or 2-channel stereo format, now surround sound in "5.1" format (5 main speakers plus one low frequency effects channel) is available in many home cinema systems, and many other multichannel audio formats are available (e.g. 6.1, 7.1, 10.2 and 22.2). In addition, new interactive apps allow users to remix musical audio, changing instrument volumes, and music games allow players to control individual instruments. Content creators therefore have to develop new ways to create and distribute their audio content to allow their content to be played back on these multichannel systems, or remixed by users to suit their own tastes. However, much audio content is still in legacy formats, mainly 2-channel stereo. We therefore need ways to "repurpose" this legacy audio content, converting these into surround sound or to the separate "stems" needed for remixable audio. The aim of this project is to develop a new approach to high quality audio repurposing, based on high quality musical audio source separation. To achieve this we will combine new high resolution separation techniques with information such as musical scores, instrument recognition, onset detection, and pitch tracking. Instead of aiming at generic source separation, we will develop algorithms designed to match the separation performance to the final target (upmixing or remixing). In parallel, we will investigate perceptual evaluation measures for source separation, remixing and upmixing, and develop new diagnostic evaluation techniques tailored to measure different aspects of the repurposed outcome. The outcomes of this project will allow music consumers to enjoy their favourite songs in interactive remixing apps and games, even where the original separate "stems" are not available. It will also allow music companies, broadcasters and sound archive holders to provide high quality upmixed versions of their large archive content, for an increasing generation of listeners with surround sound systems in the home.

Delivery of audio has become increasingly complex: originally in single channel (mono) or 2-channel stereo format, now surround sound in "5.1" format (5 main speakers plus one low frequency effects channel) is available in many home cinema systems, and many other multichannel audio formats are available (e.g. 6.1, 7.1, 10.2 and 22.2). In addition, new interactive apps allow users to remix musical audio, changing instrument volumes, and music games allow players to control individual instruments. Content creators therefore have to develop new ways to create and distribute their audio content to allow their content to be played back on these multichannel systems, or remixed by users to suit their own tastes. However, much audio content is still in legacy formats, mainly 2-channel stereo. We therefore need ways to "repurpose" this legacy audio content, converting these into surround sound or to the separate "stems" needed for remixable audio. The aim of this project is to develop a new approach to high quality audio repurposing, based on high quality musical audio source separation. To achieve this we will combine new high resolution separation techniques with information such as musical scores, instrument recognition, onset detection, and pitch tracking. Instead of aiming at generic source separation, we will develop algorithms designed to match the separation performance to the final target (upmixing or remixing). In parallel, we will investigate perceptual evaluation measures for source separation, remixing and upmixing, and develop new diagnostic evaluation techniques tailored to measure different aspects of the repurposed outcome. The outcomes of this project will allow music consumers to enjoy their favourite songs in interactive remixing apps and games, even where the original separate "stems" are not available. It will also allow music companies, broadcasters and sound archive holders to provide high quality upmixed versions of their large archive content, for an increasing generation of listeners with surround sound systems in the home.