Senior Optical Fibre R&D Engineer

PsiQuantum’s mission is to build the first useful quantum computers—machines capable of delivering the breakthroughs the field has long promised. Since our founding in 2016, our singular focus has been to build and deploy million-qubit, fault-tolerant quantum systems. Quantum computers harness the laws of quantum mechanics to solve problems that even the most advanced supercomputers or AI systems will never reach. Their impact will span energy, pharmaceuticals, finance, agriculture, transportation, materials, and other foundational industries. Our architecture and approach is based on silicon photonics. By leveraging the advanced semiconductor manufacturing industry—including partners like GlobalFoundries—we use the same high-volume processes that already produce billions of chips for telecom and consumer electronics. Photonics offers natural advantages for scale: photons don’t feel heat, are immune to electromagnetic interference, and integrate with existing cryogenic cooling and standard fiber-optic infrastructure. In 2024, PsiQuantum announced government-funded projects to support the build-out of our first utility-scale quantum computers in Brisbane, Australia, and Chicago, Illinois. These initiatives reflect a growing recognition that quantum computing will be strategically and economically defining—and that now is the time to scale. PsiQuantum also develops the algorithms and software needed to make these systems commercially valuable. Our application, software, and industry teams work directly with leading Fortune 500 companies—including Lockheed Martin, Mercedes-Benz, Boehringer Ingelheim, and Mitsubishi Chemical—to prepare quantum solutions for real-world impact. Quantum computing is not an extension of classical computing. It represents a fundamental shift—and a path to mastering challenges that cannot be solved any other way. The potential is enormous, and we have a clear path to make it real. Come join us. Job Summary: We are seeking an Optical Fibre R&D Engineer with experience in precise optical characterisation, to test, evaluate and apply advanced optical fibres in high-performance optical systems. A central part of the role is designing and carrying out precise, repeatable measurements of fibre properties, interpreting the results, and understanding how they affect system performance. The role combines experimental fibre characterisation, optical modelling and exploratory subsystem demonstrations. You will work flexibly across different fibre platforms and experimental setups, translating system needs into measurement plans and practical engineering decisions. You will work closely with specialists in optical interfaces and mechanical design, as well as with wider internal teams and external research and development partners. We welcome candidates with strong experimental R&D experience in fibre optics, guided-wave photonics or related fields, including candidates from research groups and advanced industrial R&D. This is a laboratory-based R&D role focused on measurement, evaluation and system development. Responsibilities: Design and carry out precise, repeatable measurements of optical fibre properties, including relevant loss, modal, dispersion, polarisation, coupling and environmental characteristics. Select and develop appropriate measurement methods, setups and analysis procedures for standard and non-standard fibres. Assess measurement uncertainty, repeatability and limitations; distinguish fibre behaviour from effects introduced by launch conditions, connectors, splices, fixtures or the measurement setup. Analyse and interpret experimental data, using optical modelling and analytical tools where helpful to explain observed behaviour and guide further experiments. Plan and run exploratory experiments and subsystem demonstrations using advanced optical fibre. Adapt experimental methods and setups as fibre designs, system requirements and project priorities develop. Work closely with optical-interface and mechanical-design colleagues to develop practical, well-aligned and stable fibre assemblies and test setups. Collaborate with photonics, systems and experimental teams to translate subsystem requirements into fibre measurements, evaluation criteria and development priorities. Work with external development and research partners to review data, compare technical options and guide fibre development. Document methods, results and conclusions clearly so that measurements can be reproduced and used to inform engineering decisions. Experience/Qualifications: Required PhD in optics, photonics, physics, engineering or a related field, or equivalent relevant R&D experience. Substantial research and development experience in fibre optics, guided-wave photonics or a closely related area, including developing and carrying out experiments to investigate and characterise optical systems. Strong experience designing and carrying out optical measurements, with care for precision, repeatability, calibration and sources of uncertainty. Experience taking research questions in fibre optics, guided-wave photonics or a closely related area through to engineering findings: defining the approach, developing measurement methods, analysing results and using them to guide further research or system development. Ability to interpret measurement data critically and identify how experimental setup or coupling conditions may affect results. Experience developing experimental setups and adapting methods to investigate unfamiliar or non-standard optical systems. Experience comparing experimental results with optical simulation or analytical predictions. Ability to use optical modelling or analytical methods to support experimental interpretation and guide design decisions. Strong practical problem-solving skills and sound experimental judgement. Ability to work flexibly in a small, collaborative R&D team and alongside colleagues with complementary expertise, including optical interfaces and mechanical design. Clear communication skills, including the ability to explain methods, results and limitations to technical colleagues and external partners. Preferred Experience characterising, with high precision, advanced or specialty optical fibres, or other non-standard waveguides. Experience measuring, with high precision, properties such as propagation or insertion loss, modal content, dispersion, polarisation behaviour or environmental sensitivity. Experience using fibre in optical subsystem demonstrations, beyond standalone fibre testing. Experience with optical coupling, fibre alignment, connectorisation, splicing or mechanical integration. Familiarity with optical simulation tools such as FDTD or other electromagnetic, waveguide or propagation modelling methods. Experience working with fibre research, fabrication or development groups. Experience in early-stage R&D where experimental approaches and technical priorities evolve as results emerge. PsiQuantum provides equal employment opportunity for all applicants and employees. PsiQuantum does not unlawfully discriminate on the basis of race, color, religion, sex (including pregnancy, childbirth, or related medical conditions), gender identity, gender expression, national origin, ancestry, citizenship, age, physical or mental disability, military or veteran status, marital status, domestic partner status, sexual orientation, genetic information, or any other basis protected by applicable laws. Note: PsiQuantum will only reach out to you using an official PsiQuantum email address and will never ask you for bank account information as part of the interview process. Please report any suspicious activity to recruiting@psiquantum.com . We are not accepting unsolicited resumes from employment agencies. The ranges below reflect the target ranges for a new hire base salary. Actual compensation may vary outside of these ranges and is dependent on various factors including but not limited to a candidate's qualifications including relevant education and training, competencies, experience, geographic location, and business needs. Base pay is only one part of the total compensation package. Full time roles are eligible for equity and benefits. Base pay is subject to change and may be modified in the future. Daresbury, United Kingdom <div class="pay-range"