Photonics Characterization Intern - Winter 2026

Lightmatter is leading the revolution in AI data center infrastructure, enabling the next giant leaps in human progress. The company invented the world’s first 3D-stacked photonics engine, Passage™, capable of connecting thousands to millions of processors at the speed of light in extreme-scale data centers for the most advanced AI and HPC workloads.

Lightmatter raised $400 million in its Series D round, reaching a valuation of $4.4 billion. We will continue to accelerate the development of data center photonics and grow every department at Lightmatter!

If you're passionate about tackling complex challenges, making an impact, and being an expert in your craft, join our team of brilliant scientists, engineers, and accomplished industry leaders.

Lightmatter is (re)inventing the future of computing with light! The Photonics & Silicon Engineering team's core function is the design and development of Lightmatter's photonic processors and interconnects using light instead of electrical signals for computation and communication.

They specialize in silicon photonics fabricating advanced optical components directly onto a silicon base to deliver chips and lasers with superior speed, low power and higher overall performance.

The team's innovations are critical for eliminating data bottlenecks in next-generation AI and high-performance computing Lightmatter is looking for a PhD candidate who can work in Photonics Characterization (Electrical Engineering, Physics, or related field) starting immediately with a strong understanding of Silicon Photonics and demonstrated experience in electro-optic testing of components like micro-rings and Mach-Zehnder interferometers.

The ideal candidate will leverage hands-on laboratory experience with various optical and semiconductor test equipment, and be skilled in developing and implementing automated testing using Python scripting.

This highly analytical, process-oriented individual must be capable of working independently to solve complex technical problems and translate data into actionable strategies.

Responsibilities • Participate in electro-optic testing of photonics chips/devices, leveraging hands-on laboratory experience and working with various optical instruments.

• Conduct tests and characterization of silicon photonics components, including micro-rings, optical phase shifters, and Mach-Zehnder interferometers.

• Operate a range of optical equipment such as lasers, electro-optic modulators, semiconductor optical amplifiers, PIN receivers, optical spectrum analyzers, optical vector analyzers, and optical filters.

• Utilize semiconductor test equipment, including vector network analyzers, spectrum analyzers, source-meter units, arbitrary waveform generators, and high-speed oscilloscopes.

• Design and execute testing protocols for silicon photonics chips and subsystems. • Develop and implement automated testing and system interfacing through Python scripting.

Qualifications • Recent PhD graduate OR PhD candidate in Photonics with a strong understanding of Silicon Photonics and demonstrated experience in electro-optic component testing.

• Experienced in developing and implementing automated testing systems using Python scripting, with a proven ability to translate data into actionable strategies.

• Highly analytical, process-oriented, and capable of working independently to solve complex, non-obvious technical problems in a lab environment. • Excellent written and verbal communication skills.

Preferred Qualifications • Microcontroller programming • Experience with high speed instruments • High speed communications and understanding of VNA and optical link • Understanding of high speed PCBs and/or micro electronics • Experience working in a graduate level photonics or electrical engineering lab.

• Willingness and curiosity to learn from an exciting team! We offer competitive compensation. The base salary range for this role determined based on location, experience, educational background, and market data.

Hourly Range $53—$65 USD Benefits • Comprehensive Health Care Plan (Medical, Dental & Vision) • Retirement Savings Matching Program • Life Insurance (Basic, Voluntary & AD&D) • Generous Time Off (Vacation, Sick & Public Holidays) • Paid Family Leave • Short Term & Long Term Disability • Training & Development • Commuter Benefits • Flexible, hybrid workplace model • Equity grants (applicable to full-time employees) Benefits eligibility may vary depending on your employment status and location.

Lightmatter recruits, employs, trains, compensates, and promotes regardless of race, religion, color, national origin, sex, disability, age, veteran status, and other protected status as required by applicable law.

Export Control Candidates should have capacity to comply with the federally mandated requirements of U.S. export control laws.