Photonic Technology Reliability Engineer

About Us
We are building the photonic PCB, the missing piece of technology that takes integrated photonics to scale. After a decade of research into using light to manipulate information at the micrometer scale, we found that optical integration was the main bottleneck for building high-performance optical chips. So we set out to solve it. Our 3D optical interconnect solutions connect individual photonic components into functional systems, and that work sits underneath the next wave of progress in AI, computing, sensing, and telecommunications. Position Overview We are looking for a Photonic Technology Reliability Engineer to own the reliability and manufacturability of our 3D optical interconnect technology as it moves from validated R&D to volume production. Light-based interconnects only earn their place in real systems if they survive the field — thermal cycling, ageing, mechanical stress, years of operation. Your mission is to make sure ours do: defining how we qualify, stress, and prove the robustness of our coupling solutions, and feeding what you learn back into design and process. You would be one of our first hires outside the founding team, so the standards you set early will shape how the company scales.

Key Responsibilities
• Define and own Lightspring’s reliability and qualification strategy for 3D optical interconnects: accelerated life testing, environmental and mechanical stress testing, and qualification against relevant standards (e.g. Telcordia GR-468, MIL-STD).
• Own failure analysis and root-cause investigation, closing the loop by turning findings into design, material, and process improvements.
• Lead design-for-reliability and FMEA across the product, mapping failure modes and risks from R&D designs through to volume production.
• Own the yield, performance, and reliability trajectory of products as they move from prototype through pilot to volume, and drive the roadmap for manufacturing readiness (TRL).
• Lead the transfer of qualified processes to external fabs and OSATs, and manage those partners against reliability and quality targets.
• Translate customer requirements and emerging standards into concrete reliability specifications, and represent Lightspring in technical and qualification discussions with customers, including on-site visits.
• Build the reliability data and documentation foundation — qualification reports, SPC, production documentation — in coordination with the technology integration owner. Contributions
• Feed reliability and manufacturability constraints back into process integration and the PDK / design-rule loop.
• Support cleanroom development and characterization where it accelerates qualification and industrialization.
• Participate in strategic planning and business development. About you You are happiest turning a promising result into something robust and repeatable, and you believe a technology isn’t real until it’s proven to last. You will fit well here if you want a real say in how the technology reaches production.
• PhD (ideally) or Master’s in physics, materials, electronics, photonics, or a related field, with a strong device background across design, fabrication, and test.
• Demonstrated experience in reliability, qualification, or product engineering — accelerated life testing, failure analysis, FMEA, DOE/SPC — ideally in a serious industrial semiconductor, photonics, or optoelectronics environment.
• Experience taking products or processes from R&D and prototype through pilot to volume manufacturing (scale-up, yield and reliability improvement, TRL progression).
• Familiarity with reliability standards for optical or optoelectronic components (e.g. Telcordia GR-468) is a strong plus.
• Experience translating customer requirements into technical roadmaps, and comfort in customer-facing technical discussions.
• Comfortable working hands-on with fabrication and test (e.g. lithography, epitaxy, e-beam), while motivated by the reliability and industrialization mission rather than routine execution.
• Full professional proficiency in English. French is optional. Why join
• You would be joining at the point where the early decisions still shape everything, as one of the first hires alongside the founders. The mission is real and global, and the work sits at the foundation of where photonics is heading.
• You will have access to serious facilities, including our in-house optics and microfabrication lab and the Femto-ST / Mimento clean room.
• You will hold employee shares (BSPCE) in a deeptech company building something that matters.
• You get a comprehensive healthcare plan. Location
• Besançon, France, with travel for customer engagements. Application Process
• Reach out to the team
• Fit call with the CEO (30min)
• Meet the team (30min)
• Technical interview – live assignment (60min)
• Ref calls / proposal