Rapidly Reconfigurable Integrated Photonic Systems

Optical communication systems form the backbone of the Internet and are critical
infrastructure in the modern world. With current trend network traffic growing at 25% per
year, development of communication technologies with higher capacity limits than traditional
single mode fiber are being extensively investigated. One exciting area is the development
of space division multiplexing technologies that use multimode or multi-core fibers for
increasing the capacity of fiber communications. However, these fibre types bring new
challenges such as intermodal coupling and modal dispersion that can result in errors for
transmitted data. Additionally, free-space optical (FSO) connections have become a hot topic
for network resilience for overcoming cable brakes in fiber networks, connection to low earth
orbit satellites and connecting rural communities. However, new high speed adaptive optical
systems are required for tackling the challenges facing future high capacity FSO and Fiber
communication systems.

Building on recent development with the EU project SuperPixels, integrated photonic devices
capable of high speed optical transformation have been demonstrated a potential tool for
addressing a wide range of adaptive optical challenge in communications systems. The
SuperPixel comprises independently controllable cascaded Mach-Zender interferometers,
that can rapidity change the phase and intensity of a coherent optical field such as those
used in both fiber and FSO communications. A critical element in enabling the deployment of
these technologies is the development of efficient control strategies and electronics for
interfacing SuperPixels with other network hardware. This project aims to apply field
programmable gate arrays (FPGA), such as the Xilinx Ultrascale ZCU208, for the direct
control SuperPixel for channel analysis and correction at high speeds. The control strategies
will developed to be scalable from initial demonstrations at 15kHz, with an ambition to scale
these to over 1Mhz with future super pixel platforms. This high-speed adaptive optical
platform will have broad application across communications and sensing research fields.

During the project, the use of the FPGA controlled SuperPixel as an adaptive optical system
for the mitigation of turbulence in real world equivalent FSO channels will be explored. As
the platform will be required to continuously adapt to the environment it is operating within,
the monitoring of the channel error can be used a measurement tool for the FSO channel
and the platforms usage for hybrid communication and sensing will be investigated. It is
expected that several high impact publications could results from this project, including
papers on control strategies and demonstrations of the platforms usage for communication
and sensing.