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: Professor 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.
Supervisors: Professor Anna Peacock
Co-supervisor: Professor 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.