About the Company

xLight is building the next-generation light source for semiconductor manufacturing — harnessing free-electron laser technology to deliver an industrial-grade, continuously operating light source for advanced patterning, metrology, and inspection.

About the Role

We're looking for an RF Engineer with superconducting RF coupler expertise to own the procurement, acceptance, and testing of fundamental power couplers (FPCs) and higher-order mode (HOM) couplers for our SRF cavity systems. This is a technically deep, hands-on role central to the delivery of our free-electron laser accelerator.

Responsibilities

• Procurement & Vendor Management
• Define and own technical specifications for FPC and HOM coupler procurement packages — including ceramic window assemblies, coaxial line components, bellows, flanges, and thermal intercepts
• Evaluate and qualify specialized RF coupler vendors; lead technical down-selects and source evaluations
• Author and review Statements of Work (SOWs), drawings, and acceptance criteria in coordination with mechanical and systems engineering teams
• Serve as the primary technical point of contact for coupler vendors throughout fabrication — reviewing manufacturing plans, witnessing critical process steps, and resolving non-conformances
• Manage coupler deliverable schedules and coordinate with procurement and project controls to track vendor milestones against project baseline

• Acceptance Testing
• Develop and execute incoming acceptance test procedures (ATPs) for coupler assemblies, including dimensional inspection, leak checking, vacuum qualification, and RF cold testing
• Define and own acceptance criteria for coupler RF performance: S-parameters, power handling, thermal behavior, and multipacting margins
• Operate and maintain RF test infrastructure including network analyzers, high-power RF sources, directional couplers, calorimetric loads, and data acquisition systems
• Coordinate with metrology and quality teams to ensure traceability of measurements and compliance with project specifications
• Review and disposition vendor data packages, material certifications, and non-conformance reports (NCRs); make accept/reject/rework determinations
• Maintain detailed acceptance records and contribute to the coupler configuration management database

• Conditioning & Commissioning
• Develop, execute, and iterate RF conditioning procedures for couplers at room temperature and cryogenic test stands, targeting full CW power operation while controlling field emission and multipacting as needed
• Support coupler integration into cryomodule assemblies and participate in cold testing at vertical test stands (VTS) and horizontal test cryostats (HTC)
• Troubleshoot coupler performance anomalies — field emission, vacuum events, thermal runaways — and lead root cause analysis and corrective actions
• Contribute to the development and documentation of conditioning protocols, operating procedures, and lessons learned for use across the coupler program

• RF Design Support
• Collaborate with the RF design team on coupler electromagnetic design — S-parameter optimization, multipacting simulations, and power handling analysis using tools such as CST, COMSOL, or ACE3P
• Provide RF engineering input to mechanical design reviews, ensuring that EM performance requirements are correctly translated into fabrication tolerances and assembly procedures
• Support the development of coupler test stands and RF infrastructure needed for acceptance and conditioning programs

Qualifications

• Staff Engineer – P4
• BS + 8 yrs or MS + 6 yrs in Electrical Engineering, Physics, or related field
• Hands-on experience with SRF coupler or cavity testing, RF acceptance procedures, and coupler conditioning at a national laboratory or accelerator facility
• Familiarity with high-power RF systems, UHV practices, and SRF cleanliness protocols
• Experience interfacing with specialized RF/SRF vendors on technical procurement
• Senior Staff Engineer – P5
• BS + 15 yrs or MS + 13 yrs in Electrical Engineering, Physics, or related field
• Deep expertise in FPC and/or HOM coupler procurement, acceptance testing, and conditioning programs — with demonstrated ownership across the full coupler delivery lifecycle
• Experience leading coupler programs on DOE accelerator projects (e.g., LCLS-II, APS-U, ALS-U, FRIB, SNS, or equivalent)
• Proven ability to lead cross-functional teams through vendor qualification, acceptance campaigns, and cryomodule integration

Required Skills

• Experience with CW high-power coupler systems (>10 kW average power)
• Proficiency with EM simulation tools: CST Studio Suite, COMSOL Multiphysics, ACE3P
• Semiconductor capital equipment or industrial RF system background

Pay range and compensation package

• Competitive compensation + equity (stock options)
• Full benefits: medical, dental, vision, life insurance
• 401(k) with company matching
• Flexible work: hybrid and remote options supported
• The chance to build something genuinely new in photon science and semiconductor manufacturing

Equal Opportunity Statement

xLight is an Equal Opportunity Employer. We are committed to building an inclusive team and welcome applicants of all backgrounds.