91ɫ��Ƭ

Photonic and Communications research at 91ɫ��Ƭ extends from nanometre scale semiconductor devices to sensors for biomedical applications. We explore large scale optical communication systems which enable data to be transferred at 40 Gigabytes per second.  Our department conducts research in a number of key photonic research areas and collaborates with Universities in Germany, Russia, US, Vietnam and China.  

Optical communications   

Since 2006, 91ɫ��Ƭ has firmly established its reputation world-wide as an international-leading research group in optical communications and digital signal processing (DSP) for telecommunications. In particular, we have invented a now globally accepted DSP-based signal transmission concept termed adaptively modulated optical orthogonal frequency division multiplexing (OOFDM), and has achieved a series of 12 ground-breaking experimental demonstrations of real-time high-speed OOFDM transceivers. These real-time demonstrations are enabled by a number of DSP-based symbol synchronisation and clock signal generation techniques, which was invented by 91ɫ��Ƭ. This ioned pioneering work has resulted in Fujitsu’s commercialisation of the OOFDM technique for data centres. OOFDM is currently also being considered as a technology standard by several international standards bodies such as 400GE Ethernet. Most recently, our research activities are highly focussed on exploring cutting-edge DSP technologies for seamlessly converging optical networks and mobile networks for 5G networks in order to significantly improve signal transmission and bandwidth.    

Nano lasers   

Lasers are used in many everyday applications such as cars, blue-ray discs and for treatment of cancers. Widespread efforts to miniaturise photonic devices are driven by the opportunity to develop novel nanoscale sensors and actuators suitable for wide ranging usage in e.g. environmental monitoring, bio-scientific and medical applications. 91ɫ��Ƭ manufactures the next generation of lasers that are made to be smaller than the one hundredth of the size of a human air. This opens up exciting new applications for the technology.  

Using photonics for microwave generation    

Photonic generation of high-frequency microwave signals has gained much attention over the past decade. One of the main motivations behind these studies is their potential application in radio-over-fiber (RoF) communication systems. Compared with conventional circuitry based microwave generation, photonic microwave generation offers several advantages, such as, low cost, high speed, longer transmission distance, low power consumption and less system integration complexity.  Vertical-cavity surface-emitting laser (VCSEL) is a special type of semiconductor lasers. It has many impressive characteristics, such as low cost, , low power consumption, circular beam profile, single-longitudinal mode operation, ease of fabrication and longevity, therefore, microwave photonic signal generation based on optically injected VCSEL offers low-cost and a route for low power consumption.    

Use of optical chaos    

Chaos has attracted considerable research interest due to its applications in high-speed communications, logic gates, optical time domain reflectors, LIDARs and physical random number generators. Chaos with high complexity, broad bandwidth and no time delay signature is preferred for most of its applications. Great efforts have been made to achieve the best chaos.   

Integrated Photonics and active plasmonics    

Photonic Integrated Circuit (PIC) technology is a fast-growing sector of the optics industry and is estimated to command a market share of about £1B by 2022.  Silicon and III-V material platforms are widely used for realising PICs but other materials are also being considered and developed. We develop approaches for guiding and manipulating light signals on a single photonic chip, using low losses wave guiding platforms and other components. For this purpose, we use nanofabrication processes in the departmental cleanroom.   

2D materials for photonic sensing   

Photonics technology is being increasingly proposed as a favourable optical platform for a wide range of scientific and industrial sensing applications. The state-of-the-art 2D materials such as graphene together with the advanced photonics technologies lead us to discover new phenomena, new developments and new applications. We conduct the multidisciplinary research in bio-nano-photonics fields by exploiting new emerging opportunities with the integration of fibre optic technology, nanotechnology and 2D nanomaterials for the applications in healthcare, biomedical, food safety and environmental monitoring.    

 

Schematic diagram of graphene-fiber optic biosensor. 

Super-resolution imaging 

We are the pioneers of  'microsphere nanoscope' and super-resolution techniques  based on dielectric particle superlenses made from ,  , .  Objects as small as 50 nm scale can be clearly resolved by these techniques under conventional white-lighting condition, thus offering an effective solution in turning an optical microscope into nanoscope. These works were widely publicised by major media outlets including BBC, New York Times, etc, and a significant amount of technical websites. The research was followed by many groups across the world and is currently moving towards 3D, biomedical, virology, and integrated device applications. For more details please check this featured   as well as comprehensive   chapter written by us. 

Laser material processing for industry

We perform research into laser cutting, welding, drilling, texturing, marking, cleaning, polishing and others for industrial applications. The school host a wide range of laser facilities at 91ɫ��Ƭ, including nanosecond fibre and UV lasers, femtosecond laser and CO2 lasers.  Various characterisation tools including advanced 3D laser scanning microscopes (Olympus OLS5000 and DSX1000) are also available for the precise measurement and characterisation of laser-processed samples. The research is currently supported by major pan-wales project “” which supports welsh industry (all sectors including electronics, optics, aerospace, automotive, energy, nuclear, etc.) in developing new products, process and services. We have unique capability in direct laser nano marking using specially developed superlens with sub-100 nm resolution.