Frequency Comb Photonics Engineer

ABOUT US Infleqtion is a global quantum technology company solving the world’s most challenging problems. The company harnesses quantum mechanics to build and integrate quantum computers, sensors, and networks. From fundamental physics to leading edge commercial products, Infleqtion enables “quantum everywhere” through our ecosystem of devices and platforms. Our mission is to commercialise atom-based quantum products that provide orders of magnitude improvements in performance and computing applications. LOCATION Infleqtion has offices in the USA, United Kingdom, and Australia. This is a full-time position mainly in our Kidlington, Oxford office with the occasional requirement to be in the National Quantum Computing Centre, Harwell. Work from home permitted up to 2 days per week based on business needs and manager approval. POSITION SUMMARY Infleqtion UK is seeking a Frequency Comb Photonics Engineer to support the development, characterisation, and integration of optical frequency comb technologies for quantum systems. This is a hands-on technical role focused on designing, building, testing, and optimising frequency comb systems, including micro-comb and PIC-based approaches. The successful candidate will work closely with photonics, quantum systems, electronics, and software teams to evaluate how compact frequency comb technologies can support applications such as precision timing, sensing, laser stabilisation, atom addressing, and quantum system integration. JOB RESPONSIBILITIES The duties and responsibilities outlined below include essential functions of the role. Depending on business needs, this role may perform a combination of some or all of the following duties. Duties, responsibilities, and activities may change, or new ones may be assigned. Develop, test, and characterise optical frequency comb systems for quantum technology applications. Support design and testing of photonic components relevant to comb generation, including resonators, lasers, modulators, passive devices, and integrated photonic circuits. Build and operate optical test setups for frequency comb characterisation, stabilisation, and performance validation. Perform laser characterisation, including optical spectra, frequency noise, relative intensity noise, linewidth, and stability measurements. Characterise modulated laser systems, including high-speed waveform measurements and RF/optical measurement setups. Develop automated test methods and data analysis workflows for frequency comb and photonic device characterisation. Collaborate with integrated photonics, quantum systems, electronics, and software teams to integrate frequency comb technologies into larger systems. Work with external foundries, suppliers, and packaging partners as needed to support device development and evaluation. Document experimental results, generate technical reports, and present findings to internal stakeholders. Support risk assessments, safe operating procedures, and good laboratory practice for optical and laser-based systems.