Towards Low-Loss Active Integrated Devices for Quantum Applications

Lead Research Organisation: University of Southampton
Department Name: Optoelectronics Research Centre


Quantum computing and communications require feedforward control of single photons for many applications. Currently commercially available switches are either too slow, or are too lossy to be practical. This project aims to rectify this by investigating switching of light, with the aim of making a switch with 0.1dB transmission loss, a switching time of 10 ns and a switching rate of 1MHz, in a scalable platform.

Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509747/1 01/10/2016 30/09/2021
1921182 Studentship EP/N509747/1 29/09/2016 30/06/2020 James Field
Description This research has developed a framework for modelling and fabrication of spectrometers using a new platform, which enables much smaller size, and greater stability than those already in existence. The work focused around use of modelling to try and optimise and improve the spectrometer output.
Exploitation Route The software library is already in use by other members of the research group, where it is being used to investigate bend loss in laser written waveguides. This should reduce the loss in our reconfigurable quantum circuit devices, hopefully allowing our devices to probe the quantum regime.

Early work on switching based devices have resulted in a further two Ph.D projects to examine different methods of switching in more detail.
Sectors Agriculture, Food and Drink,Digital/Communication/Information Technologies (including Software)

Title Laser writing control library 
Description C++ library used to control equipment used in UV laser writing of waveguides and Bragg gratings. Controls 4-axis stage system along with phase modulator for laser control. Abstracts control of low level systems from design of devices to reduce device variability and code complexity. Enables use of sample rotation during writing. 
Type Of Technology Systems, Materials & Instrumental Engineering 
Year Produced 2019 
Impact Rotation of samples during writing has been used to create Bragg gratings with a varying blaze angle along their length. This resulted in an oral presentation in Photonics West 2020. Work is ongoing to use this software to investigate the loss of curved waveguides for couplers in quantum applications.