Optics, Photonics, and Quantum Information Science
- [(ETH - Zurich) - Gian Marco Castelberg]
- Optics and Photonics
Optics and photonics are the disciplines that study the fundamental properties of light and exploit them in practical applications. Optics and photonics cover the entire electromagnetic spectrum, from high-energy gamma rays and X-rays, through the optical range of ultraviolet, visible and infrared light, to long-wavelength microwaves and radio waves.
Although the study of light has been carried out for centuries, it is only in the last 40 years that optics and photonics have become the dominant fields, affecting almost every aspect of our lives, from entertainment, medicine, defense to communication. is the main impact technology, powered by optical technology.
The 21st century is the "age of light", a century that sees optics and photonics as major influencing technologies, and in some cases enabled by electronics.
- Quantum Photonics
Quantum photonics is the science of generating, manipulating and detecting light in regimes where it is possible to coherently control individual quanta of the light field (photons). Historically, quantum photonics has been fundamental to exploring quantum phenomena, for example with the EPR paradox and Bell test experiments. Quantum photonics is also expected to play a central role in advancing future technologies, such as Quantum computing, Quantum key distribution and Quantum metrology. Photons are particularly attractive carriers of quantum information due to their low decoherence properties, light-speed transmission and ease of manipulation. Quantum photonics experiments traditionally involved 'bulk optics' technology - individual optical components (lenses, beamsplitters, etc.) mounted on a large Optical table, with combined mass of hundreds of kilograms.
Our interests are wide ranging from quantum optics, semiconductor physics, material science, nonlinear photonics to application of photonics for industrial applications. Our research is organised into the following themes: Quantum Photonics and Quantum Information, Ultrafast Photonics, Applied Photonics, etc..
- [The electromagnetic spectrum from lowest energy/longest wavelength (at the top) to highest energy/shortest wavelength (at the bottom). (Credit: NASA's Imagine the Universe)]
- Integrated Quantum Photonis
Integrated quantum photonics, uses photonic integrated circuits to control photonic quantum states for applications in quantum technologies. As such, integrated quantum photonics provides a promising approach to the miniaturisation and scaling up of optical quantum circuits.The major application of integrated quantum photonics is Quantum technology:, for example quantum computing, quantum communication, quantum simulation, quantum walks and quantum metrology.
Integrated quantum photonics application of photonic integrated circuit technology to quantum photonics, and seen as an important step in developing useful quantum technology. Photonic chips offer the following advantages over bulk optics:
- Miniaturisation: Size, weight and power consumption are reduced by orders of magnitude by virtue of smaller system size.
- Stability: Miniaturised components produced with advanced lithographic techniques produce waveguides and components which are inherently phase stable (coherent) and do not require optical alignment
- Experiment size: Large numbers of optical components can be integrated on a device measuring a few square centimetres.
- Manufacturability: Devices can be mass manufactured with very little increase in cost.
Being based on well-developed fabrication techniques, the elements employed in Integrated Quantum Photonics are more readily miniaturisable, and products based on this approach can be manufactured using existing production methodologies.
- Materials
Control over photons can be achieved with integrated devices that can be realised in different material platforms such as silica, silicon, gallium arsenide, lithium niobate and indium phosphide and silicon nitride.
Silicon is the most widely used material in modern electronics industry in the world, due to its natural abundance, semiconductor/doping property, mass production, and capability to be densely integrated. It is a long-awaited goal to amalgamate photonics with the advantages of silicon, i.e. silicon photonics.
In the field of electronics, the key success relies on nonlinear components, such as transistors, that can control electric signal via voltage or current, i.e. all-electric control. Similarly, in silicon photonics, light-control-light, or equivalently all-optical control, is a highly desirable function. However, the optical nonlinearity of silicon is too weak to achieve efficient all-optical control.
- Quantum Information Science
Advances in quantum technologies, including quantum information science, have the potential to transform and revolutionize computing, medicine, manufacturing, artificial intelligence, communications, national defense, and more.
Quantum mechanics is the field of physics and the theoretical foundation of quantum information science. Quantum Information Science is an emerging field with the potential to cause revolutionary advances in fields of science and engineering involving computation, communication, precision measurement, and fundamental quantum science.
Quantum information science is an interdisciplinary field that looks to understand the analysis, processing, and transmission of information through the lens of quantum mechanics principles. It combines the study of Information science with quantum effects in physics. It includes theoretical issues in computational models as well as more experimental topics in quantum physics including what can and cannot be done with quantum information.
The term quantum information theory is also used, but it fails to encompass experimental research in the area and can be confused with a subfield of quantum information science that studies the processing of quantum information.
[More to come ...]
