Headed by Professor Anna Peacock, the Nonlinear Semiconductor Photonics Group's focus is in the development of novel semiconductor waveguide platforms; from the design and characterisation stage, through to the demonstration of practical all-optical nonlinear devices.
The group has a full complement of experimental and numerical expertise to support the development, fabrication and application of a wide range of nonlinear photonic devices. It works in close collaboration with several groups across the Faculty of Physical Sciences and Engineering (FPSE) in particular, the Silicon Photonics group.
Supervisor: Prof. Anna Peacock
Semiconductor photonics is fast becoming one of the most active areas of research, offering optoelectronic solutions for a wide range of applications not only in telecoms, but also in medicine, imaging, spectroscopy, and sensing. Within this field, a subdivision that is gaining increased momentum is semiconductor nonlinear photonics as the materials display a number of important nonlinear effects that can be used to generate and process signals at ultrafast speeds.
This research project will follow the development of semiconductor devices fabricated both from conventional planar waveguides on-chip as well as those based on an emerging platform that incorporates semiconductor materials directly into the cores of optical fibres. In particular, the semiconductor fibre platform offers a unique possibility to seamlessly link semiconductor technologies with the silica fibre infrastructures that are used to transmit light around the globe – one of the key challenges facing the mass uptake of integrated photonic chips.
A number of devices will be explored including amplifiers, frequency converters, couplers, all-optical modulators and sensors and will involve both theoretical modelling of the waveguide structures and systems as well as construction and characterisation of the devices.
Supervisor: Prof Anna Peacock
Co-supervisor: Dr Sakellaris Mailis and Dr Harold Chong
Silicon materials are synonymous with the microelectronics industry and, in particular, the processors used in everyday gadgets such as mobile phones, tablets, digital radios and televisions.
More recently, due to its favourable optical properties in the telecoms band, silicon has gained popularity in the field of optical information technologies, i.e., using photons instead of electrons to transmit information. Bringing these two research areas together on an integrated platform will have huge technological consequences. However, there is a challenge: silicon photonic devices are typically fabricated via complex processing of expensive single crystal wafers, which renders multi-device integration difficult.
This project seeks to develop a simple, low cost laser materials processing procedure to fabricate high quality polysilicon photonic platforms that will ease issues associated with optoelectronic integration.
The work will have elements of:
• Materials growth (deposition of amorphous silicon and other semiconductors).
• Device fabrication (photolithographic patterning and laser crystallization) of various integrated photonic components such as couplers, resonators, modulators etc.
• Optical characterization and device benchmarking.
This project is in collaboration with the Nano Group (Dr Harold Chong) and will draw on the state-of-the-art facilities within the Southampton Nanofabrication Centre.
Supervisors: Prof Anna Peacock
Co-supervisor: Prof Goran Mashanovich
Recently there has been tremendous interest in migrating group IV (silicon and germanium) photonics beyond telecoms and into the mid-infrared. Much of the motivation for this move stems from the potential to develop devices for use in important application areas such as environmental sensing, homeland security, and medicine.
However, there are a number of other compelling reasons to move to this wavelength regime where the semiconductor materials offer extended low loss transmission windows (1-6µm for silicon and 2-14µm for germanium). Specifically for nonlinear applications, silicon and germanium exhibit strong nonlinear coefficients and reduced nonlinear absorption in this region, so that the device efficiency can be greatly increased.
This project will start with the nonlinear characterisation of mid-infrared waveguides fabricated from various silicon and germanium platforms to establish a set of design criteria for device construction. The optimised waveguides will then be used to demonstrate nonlinear frequency conversion through Raman amplification, four-wave mixing, and supercontinuum generation for application in spectroscopy and sensing.