Quantum Communication System Developer

Company: Xen Quantum
Apply for the Quantum Communication System Developer
Location: Cambridge
Job Description:

About Us: Xen Quantum is building next-generation quantum communication systems based on silicon photonics and a 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 characterise 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 characterise optical and electro‑optic subsystems and prototypes.
  • Analyse 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 characterise optical systems independently.

Technical Skills

  • Hands‑on experience with optical system construction and characterisation.
  • Fibre‑optic systems experience (lasers, modulators, detectors, fibre components).
  • Electro‑optic 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.

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Posted: June 19th, 2026