Diagnostics Mechanical Engineer

xLight is building the world's most powerful laser to revolutionize semiconductor lithography, metrology, and other critical applications. Our approach harnesses the power of free-electron lasers, building on accelerator technology in use globally at scientific user facilities. Extending this technology, we are developing industrial-grade light sources, engineered for continuous operation, to meet the sophisticated demands of next-generation patterning, metrology, and inspection applications. Join us in this new revolution. xLight is seeking a mid-career Mechanical Engineer to design and develop precision diagnostic hardware for next-generation free electron laser systems. You will partner with scientists and engineers to create ultra-high vacuum compatible systems involving precision in-vacuum motion, beam‑induced thermal management, alignment, and wakefield‑aware mechanical design in demanding industrial environments. In this role, you will own designs from concept through fabrication, installation, and first beam, collaborating across interdisciplinary teams including national labs and external vendors. The ideal candidate thrives in a fast‑paced startup environment and enjoys solving complex engineering challenges at the intersection of mechanical systems, particle accelerators, and advanced laser technology. Key Responsibilities Design and integrate precision in‑vacuum motion systems: actuators, stages, and probe mechanisms with high repeatability, vibration control, and fast‑scan dynamics under realistic duty cycles. Lead thermal and mechanical design for beam‑intercepting components, including FEA analysis, cooling strategies, and materials selection. Collaborate with RF and simulation engineers on wakefield impedance‑aware mechanical designs. Design ultra‑high vacuum hardware including vacuum vessels, flange systems, weldments, flange systems, bakeout‑compatible assemblies, and particle‑free integration processes. Develop engineering specifications and interface control documents for diagnostic devices and beamline integration. Review vendor‑supplied designs, resolve tolerance/interference issues, and support fabrication release. Coordinate installation, alignment, testing, validation, and documentation of mechanical systems and prototypes. Required Qualifications BS or MS in Mechanical Engineering or related field. 4+ years of experience in mechanical design for particle accelerators, beamlines, large‑scale physics instrumentation, or comparable ultra‑high vacuum environments. Hands‑on experience with designing precision in‑vacuum motion systems, thermal analysis/FEA, and UHV design practices. Experience authoring interface control documents and coordinating with vendors for major accelerator subsystems, including build‑to‑print manufacturing support. Proficiency with Siemens NX (or similar 3D CAD platform) and GD&T. Preferred Qualifications Experience with accelerator diagnostics, FEL/ERL systems, or high‑average‑current accelerator hardware. Background in radiation‑environment design, survey/alignment workflows, or major accelerator subsystem integration. Understanding of wakefield and RF impedance considerations for beam‑intercepting devices. Experience working with vendor coordination, motion controls, or PID tuning. What We Offer 100% Company‑funded health insurance for employee Company funded Life Insurance and disability insurance 401k contribution. 100% up to 3% of compensation, plus 50% match between 3% and 5%. Immediately vested. Flexible Paid Time‑Off, Sick leave and Company Holidays Company Paid Two‑weeks Winter Break Flexible Hybrid Work Model Catered Breakfast, Lunch, and Dinner at Palo Alto office The pay range for this position reflects the minimum and maximum target for new hire salaries at commencement of employment and is expected to be between USD$115,000-160,000/year. However, base pay offered may vary depending on multiple factors, including role, job‑related knowledge, skills, relevant education and experience. The total compensation package for this position may also include other elements, including equity, and a full range of benefits. Details of all benefits will be provided if an employee receives an offer of employment. xLight Inc. is an Equal Opportunity Employer. Our policy is clear: there shall be no discrimination on the basis of age, disability, sex, race, religion or belief, gender reassignment, marriage/civil partnership, pregnancy/maternity, or sexual orientation. We are an inclusive organization and actively promote equality of opportunity for all with the right mix of talent, skills and potential. We welcome all applications from a wide range of candidates. Selection for roles will be based on individual merit alone. #J-18808-Ljbffr xLight Inc.