Lead Optical Systems Engineer

# Lead Optical Systems Engineer## About

En entreprise, comme en musique, tout est une question de tempo. Depuis 2018, nous réunissons des **consultant·e·s passionné·e·s, curieux·ses et ambitieux·ses,** uni·e·s par une même conviction : mettre leur expertise au service des défis numériques, sectoriels et industriels de nos clients.

Notre mission ? **Accélérer les transformations** en combinant excellence opérationnelle, curiosité et audace. Nous accompagnons des acteurs majeurs du **luxe, du retail, de l’énergie, du transport, du tourisme, de la banque ou encore de l’assurance** — partout où la technologie rencontre l’humain.

Nous aimons la tech quand elle connecte et libère les potentiels. Nos consultant·e·s ne se contentent pas de conseiller : ils construisent, testent, mettent en production, mesurent, ajustent et recommencent. **Avec nos clients, nous faisons partie du jeu, du début à la fin**.

Notre organisation repose sur une **culture de la confiance, de l’apprentissage et de la collaboration**. Nous avons conçu un cadre unique qui accompagne chaque e

Xalté·e à chaque étape de sa carrière, avec des rôles clairs, des communautés actives et des rituels qui renforcent le collectif. Nos **e

Xaltemps** trimestriels, notre **e

Xalt Academy** et nos projets internes sont autant d’occasions d’apprendre, de partager et de grandir ensemble.

Aujourd’hui présents en **France, au Canada, aux États-Unis, au Royaume-Uni, en Belgique, en Espagne, au Portugal et à Monaco**, nous sommes portés par un engagement fort et une énergie contagieuse.

Parce qu’apprendre est notre discipline, agir notre obsession et réussir ensemble notre plus belle victoire.**Pulse. Make. Learn.** Trois mots qui rythment notre quotidien. Et peut-être bientôt le tien?## Job Description

Our client is an innovative and fast-growing technology company developing advanced optical communication and photonics-based systems for demanding applications.

As part of its growth and the strengthening of its optical engineering capabilities, we are looking for a **Lead Optical Systems Engineer**.

Reporting to the R&D and Engineering teams, you will take ownership of the optical discipline across the company’s products. You will work across the full development lifecycle of optical systems: from architecture and modelling through to integration, alignment, characterisation and validation on dedicated test benches.

You will join an already structured technical environment, with optical designs, analyses, error budgets and operating test benches under configuration control. Working closely with a Senior Optical Architect, who will act as a technical authority and mentor, you will take operational and technical ownership of the discipline, while ensuring that optical knowledge, methods and best practices are documented and sustained across the organisation.* **System Architecture & Trade-offs:*

• Participate in system-level analyses and architecture trade-offs, including link and radiometric budgets, requirements flow-down to optical subsystems, and arbitration between optical, mechanical, thermal, electrical, mass and cost constraints.* **Optical Design:*
• Design optical trains and produce complete optical prescriptions suitable for manufacturing or procurement, including materials, coatings, tolerances, expected performance and acceptance criteria.* **Modelling & Simulation:*
• Build and run optical models using ray-tracing software to assess image and beam quality, transmission, efficiency, stray light, polarisation and tolerance sensitivity.* **First-Principles Modelling:*
• Develop and maintain analytical models to validate numerical simulations, covering beam propagation, diffraction, optical coupling, radiometry and optical-link performance.* **Optical Error Budgets:*
• Define, maintain and defend optical error budgets during design reviews, ensuring consistency between predicted performance, available margins and measured results.* **Integration & Test:*
• Lead the transition from design to hardware, including component and supplier selection, definition of assembly and alignment procedures, and follow-up of Assembly, Integration & Test (AIT) and characterisation campaigns.* **Optical Ground Support Equipment:*
• Define, specify and procure the optical ground support equipment, test benches and metrology tools required to demonstrate product compliance, as well as the associated test strategy.* **Model-to-Test Correlation:*
• Compare predicted and measured performance, analyse discrepancies, identify root causes and feed findings back into optical models and error budgets.* **Supplier Management:*
• Lead technical interactions with optics manufacturers, coating suppliers, integration partners and laboratories, including specifications, RFQs, design reviews, acceptance criteria and incoming inspection.* **Technical Leadership:*
• Help develop the company’s optical capability by mentoring engineers and interns, formalising methods and ensuring the technical documentation and optical baseline remain robust, traceable and transferable.## Preferred Experience* **Education:*
• Master’s degree, Engineering degree or Ph

D in Optics, Photonics, Physics, Optical Engineering or a related discipline.* **Professional Background:*

• Significant experience in the design, analysis, integration and validation of complex optical systems. You have ideally delivered an optical system end to end—from design and modelling through to manufactured hardware, alignment and testing.* **Technical Expertise:** + Strong command of at least one professional optical design and analysis software package: **FRED**, **Zemax Optic

Studio**, **Code V** or equivalent. + Solid grounding in geometrical and physical optics, including beam propagation, diffraction, coupling, radiometry and polarisation. + Experience in non-sequential modelling, stray-light analysis, Monte Carlo tolerancing and the definition of realistic compensators. + Experience in optical prescription writing, thin-film and coating specification, as well as manufacturing tolerances. + Programming and scripted-analysis skills, particularly in **Python**; familiarity with Mathematica is a plus. + Good command of optical metrology techniques, including interferometry, wavefront sensing, autocollimation, beam profiling, power measurement and spectral measurement.* **System Engineering Mindset:*

• You are comfortable building and owning error budgets, justifying requirements and making technical trade-offs at the interface of optics, mechanics, thermal engineering, electronics and industrial constraints.* **Relevant Industry Experience:*
• Experience in space systems, precision instrumentation, photonics, optical communications, defence electro-optics or similarly demanding environments would be highly valued.* **Mindset:*
• You are motivated by technical ownership and able to lead a discipline, challenge technical decisions constructively and make sound engineering judgements. You are equally comfortable developing models and working hands-on in the lab, translating measurement results into engineering decisions.* **English:*
• Professional working proficiency in English, with the ability to write technical documentation and communicate effectively with international suppliers and partners.## Additional Information
• Contract Type: **Full-Time**
• Start Date: **02 December 2026**
• Location: **Paris**
• Education Level: **Master's Degree**
• Experience: **> 5 years*** **Occasional remote authorized**
• Salary: **between 40000€ and 60000€ / year**

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