Mathias Weisen

University of Southampton · Optoelectronics Research Centre (ORC)

Integrated photonics is a versatile technology in which optical components are integrated in a single photonic chip. This has a wide range of applications including in telecommunications, optical information processing and quantum computing. A highly flexible integrated photonics platform has previously been developed at the ORC for inscribing wave...

We propose and investigate theoretically the use of bi-directional propagation of light in silica integrated coupled waveguide structures for linear optical processing of fiber-coupled photons. We show that the class of linear operations that can be implemented in such a system is given by symmetric and unitary matrices. We present how an arbitrary...

We propose and numerically simulate a new and highly compact integrated 4x4 mode coupler based on two single-mode waveguides exploiting both forward and backward propagating directions to double the number of modes. The two parallel waveguides are coupled via long and short-period gratings to the co- and counterpropagating directions, respectively,...

We propose and investigate numerically a new kind of integrated optical waveguide coupler. Two waveguides with tilted Bragg gratings couple selectively to a discrete counterpropagating cladding mode that acts as an intermediary to transfer power between the waveguides. This gives a highly versatile platform that can act as a low-loss coupler with a...

The measured D-D neutron rate of neutral beam heated JET baseline and hybrid H-modes in deuterium is found to be between approximately 50% and 100% of the neutron rate expected from the TRANSP code, depending on the plasma parameters. A number of candidate explanations for the shortfall, such as fuel dilution, errors in beam penetration and effecti...