Quantum Communication System Developer

Xen Quantum Ltd; Cambridge; On-site; GBP 40,000 - 60,000; Full time

Benefits offered by this job

Company shares options plan

Enhanced annual leave (25 days + bank holidays)

Flexible working options

Job summary

Xen Quantum Ltd in Cambridge is seeking a Quantum Communication System Developer to join as one of the first technical hires. You will develop and characterize quantum key distribution (QKD) systems, design photonic integrated circuits, and work closely with founders to shape both technology and engineering culture.

The ideal candidate will possess an MSc or PhD in Physics or Engineering, with strong hands-on experience in quantum optics and optical communications. This role offers a competitive salary and flexible working options.

Qualifications

• Demonstrated excellence in experimental quantum optics and optical communications.
• At least 3 years of hands-on laboratory experience.
• Proven ability to design, build, and characterize optical systems independently.

Responsibilities

• Develop, integrate, and characterize quantum key distribution (QKD) systems.
• Design, test, and evaluate photonic integrated circuits (PICs).
• Build and characterize optical and electro-optical subsystems.

Skills

Hands-on experience with optical system construction and characterisation

Fibre-optic systems experience

Electro-optical lab experience

Experience building, characterising, and controlling QKD systems

Scientific programming experience (Python, C/C++)

Experience with Linux-based systems and version control

Statistical data analysis and visualisation

Experience with numerical modelling and simulations

Strong project management and self-organisation skills

Education

MSc or PhD in Physics, Engineering, or a closely related field

Job description

About us

Xen Quantum is building next-generation quantum communication systems based on silicon photonics and patented architecture, enabling practical and scalable quantum key distribution (QKD). Our technology simplifies implementation and lays the foundation for high-volume manufacturing and real-world deployment.

Position Overview

We're looking for a Quantum Communication System Developer to join as one of our first technical hires and play a defining role in shaping both our technology and the engineering culture.

This is a hands‑on role at the intersection of quantum optics, photonics, cryptography and system engineering – spanning laboratory development, system integration, and early field deployment with customers.

What You'll Do

• Develop, integrate, and characterize quantum key distribution (QKD) systems, with a focus on optical subsystems and protocol execution


• Design, test, and evaluate photonic integrated circuits (PICs) for quantum communication applications


• Build and characterize optical and electro‑optical subsystems and prototypes


• Analyze experimental data and feed results back into system and product design


• Design and execute experiments, pilot trials, and early customer deployments


• Work closely with founders and collaborators to develop deployable systems

What We're Looking For

Education & Experience

• MSc or PhD in Physics, Engineering, or a closely related field


• Demonstrated excellence in experimental quantum optics and optical communications


• At least 3 years of hands‑on laboratory experience in relevant topics


• Proven ability to design, build, and characterize optical systems independently

Technical Skills

• Hands‑on experience with optical system construction and characterisation


• Fibre‑optic systems experience (lasers, modulators, detectors, fibre components)


• Electro‑optical lab experience, including familiarity with RF signals and measurements


• Experience building, characterising, and controlling QKD systems


• Scientific programming experience (Python and relevant libraries; C/C++ highly valued)


• Experience with Linux‑based systems and version control (git)


• Statistical data analysis and visualisation


• Experience with numerical modelling and simulations


• Strong project management and self‑organisation skills, independently planning and executing work while reliably meeting timelines, technical milestones, and other constraints

Nice to Have

• Experience with photonic integrated circuit design and characterisation


• Experience with field trials or deployed optical systems


• Exposure to customer‑facing technical work

This is a wish list, not a requirements list – if you have a technical background, are excited about what we’re building and want to be part of an early‑stage start‑up, we want to hear from you

How You Work

• Strong communication and collaboration skills


• Creative and flexible problem‑solver, able to work around real-world constraints


• Comfortable operating independently in an early‑stage environment


• Willing to take ownership of the responsibilities associated with the role, and help define the technology development

Compensation & Benefits

• £40,000 – £60,000 pa, depending on experience


• Company shares options plan


• Enhanced annual leave (25 days + bank holidays)


• Primarily in‑person working (in Cambridge, UK), with flexible options where possible


• Early‑hire role with genuine scope to grow with – and help shape – the business