Do you dream of designing the photonic engines at the heart of tomorrow’s communication and quantum systems? At Lightium, we’re developing cutting-edge photonic integrated circuits (PICs) based on thin-film lithium niobate (TFLN) — and now we are expanding our platform with integrated III-V active devices. We are looking for a PIC Design Engineer with deep expertise in modeling and designing active photonic components to join us on this next milestone.

Position Summary

We seek a PIC Designer with a strong focus on III-V-based active components, including lasers, semiconductor optical amplifiers (SOAs), and photodetectors. You will lead the simulation, design, and optimization of these devices, develop compact models for our process design kit (PDK), and support the integration of these elements into complete photonic circuits. Your work will directly shape the active device layer of our hybrid TFLN platform.

Key Responsibilities

Active Device Design: Design and optimize III-V-based layer stacks for lasers, SOAs, and photodetectors using FEM, FDTD, and semiconductor modeling tools. Simulate optical, electrical, and thermal performance to guide layer stack design, device layout, and fabrication.

Hybrid Integration: Collaborate on co-design between TFLN passive circuits and III-V active regions. Ensure alignment between optical mode matching, coupling strategies, and process constraints.

PDK Modeling: Develop compact physical and behavioral models of active devices for use in system-level simulations. Integrate them into our PDK in tools such as GDS Factory, Luceda Photonics -IPKISS, Nazca, or Synopsys.

Circuit Integration: Support circuit-level layout and simulation of PICs, incorporating both passive and active components. Contribute to the co-simulation of optical and RF behavior at the circuit level.

Collaboration: Work closely with the fabrication, characterization, and packaging teams to validate designs, support test plans, and iterate on performance improvements.

Technical Expertise: Stay on top of advances in III-V integration, hybrid bonding, and active PIC packaging. Apply learnings to enhance Lightium’s platform continuously.

Documentation: Maintain clear records of device designs, simulation parameters, and integration strategies.

Customer & Project Support: Occasionally support customer designs or public-funded R&D projects, contributing technical expertise and simulation input.

What Our Ideal Candidate Brings

Education & Experience: A PhD in III-V design or 3+ years of III-V work experience, including simulation softwares in the areas of photonics simulation (COMSOL or Lumerical) and band gap simulation (Silvaco, Photon Design, Ansys Semiconductor, etc.). Work experience in the PIC industry would be very positive.

Additional Knowledge: Advanced experience with RF high speed (UTC detectors) and RF simulation tools (HFSS, CST, etc.). Experience with micro-transfer printing and coupon or tether design, photonic characterization and microfabrication. 

Problem Solving & Proactiveness: Deep analytical skills with the ability to model and improve complex multi-physics systems. Autonomy to identify, own, and solve challenges.

Adaptability: The ability to thrive in a fast-paced startup environment, demonstrating flexibility and resilience in the face of change.

Communication Skills: A collaborative mindset with the ability to present technical work clearly to diverse teams. Fluency in English is required.

What We Offer

• A unique opportunity to lead a cutting-edge manufacturing initiative in the rapidly growing field of photonics.
• A collaborative and innovative work environment where your contributions will shape the future of telecommunications, datacom, and beyond.
• Competitive compensation and benefits package, including an employee stock option plan (ESOP) which reflects your experience and expertise.
• Become a key player in an early-phase startup and join a motivated and energetic team. You will have the unique opportunity to create, grow, and develop your professional skills at a fast pace.

We'd love to hear from you if you're passionate about building new tech from the ground up and thrive in a collaborative and result-driven environment.

Lightium is an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees.