Simulating pump rejection filters for integrated photonic quantum information processing

Student thesis: Master's ThesisMaster of Science (MSc)


Quantum information technologies have wide-ranging and novel applications. A promising approach to their implementation is the use of integrated photonics. For this application, integrated photonic chips require the creation and detection of single photons. Nonlinear processes used in the creation of heralded single photons, such as spontaneous four-wave mixing, require effective rejection filtering of bright pump light. In this work, micro-ring resonators in SOI are explored in this filtering capacity. Simulations of these resonators with the addition of absorptive nanowires were produced. The nanowire has the effect of reducing build-up of the electric field within the ring, increasing extinction and suppressing unwanted nonlinear effects within the cavity. Simulations of these rings with MoSi, Cr and NbN nanowires were conducted. Systems made up of N≤3 rings in a cascaded configuration are examined for their filtering properties. The maximum extinction recorded was found to be 46.8dB in a three-ring design with 3μm of MoSi nanowire deposited with width 400nmand height 4.7nm. The maximum FWHM presented for these rings is 1.8nm. The advantages and disadvantages of this approach are discussed, materials are compared, and suggestions for further work are made.
Date of Award28 Sep 2021
Original languageEnglish
Awarding Institution
  • The University of Bristol
SupervisorEdmund G H Harbord (Supervisor) & Dondu Sahin (Supervisor)

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