Senior Laser Test & Characterization Engineer

ABOUT NEUROPHOS The demand for new data centers and AI compute is rapidly outpacing the planet's energy capacity. Digital solutions are hitting a power wall as we approach the physical limits of traditional silicon. Conquering this bottleneck means rethinking the fundamental architecture of inference compute. The industry's current path can't meet the need, so we're taking a different approach. Instead of traditional electronic circuits, we use silicon photonics and an active, programmable metasurface to perform matrix multiplications at the speed of light. Our optical cells are 10,000x smaller than traditional photonic components, enabling unprecedented density. By using photonics instead of electricity, our chips become more efficient as they scale. This architecture will deliver up to 100 times the energy efficiency of existing solutions while significantly improving performance for large-scale AI inference. We’ve assembled a world-class team of industry veterans and recently raised a $110M Series A https://www.neurophos.com/110m-raise led by Gates Frontier. Participants include M12 (Microsoft’s Venture Fund), Carbon Direct Capital, Aramco Ventures, Bosch Ventures, Tectonic Ventures, Space Capital, and others. Join us and shape the future of computing! Location: Austin, TX. Full-time onsite position. Reports To: Photonics Characterization Lead FLSA Status: Exempt POSITION OVERVIEW Neurophos is hiring an electro-optics engineer to build and run the test and characterization of the lasers and optical amplifiers behind our photonic AI processors. You will own the bench that measures our narrow-linewidth seed lasers and high-speed pulsed sources. This includes relative intensity noise (RIN), phase noise, timing jitter, linewidth, pulse shape, and the RF drive that generates the pulses. Your results will guide source selection and the performance specs we set with vendors. You will work closely with the amplifier, transmit PIC, receiver, and electronics teams. This is a hands-on lab role: you will build setups, collect data, and turn it into clear pass/fail answers. KEY RESPONSIBILITIES - Design, build, and maintain the laser and amplifier characterization bench, including polarization-maintaining fiber setups at watt-level optical power. - Measure RIN from ~kHz to tens of GHz at the source and through amplifier chains. This includes shot-noise subtraction and integration over the receiver bandwidth. - Measure laser linewidth and frequency noise (delayed self-heterodyne or equivalent), wavelength stability, side-mode suppression, and polarization extinction ratio. - Characterize high-speed pulsed sources at tens of GHz: pulse width and shape (log scale), pulse-to-pulse amplitude uniformity, and timing jitter. - Measure RF phase noise of synthesizers and clock chains, and residual (additive) phase noise of the full electro-optic chain. Convert phase noise to integrated jitter. - Set up and run the RF drive for electro-optic modulators: Ka-band amplifiers, filters, phase alignment, and modulator bias control. - Characterize optical amplifiers: gain, noise figure, saturation, added RIN, and correlated versus uncorrelated noise between channels. - Automate measurements and build a data pipeline (Python, instrument control) to make results repeatable and traceable. - Turn data into specs: write test procedures, set pass/fail thresholds, and evaluate vendor samples against them. - Work with vendors on sample evaluation and data requests, and with internal teams on system-level noise and timing budgets. QUALIFICATIONS - MS or PhD in electrical engineering, physics, optics, or photonics. - Hands-on lab work with narrow-linewidth lasers (DFB, external-cavity or fiber lasers) at 1550 nm, from industry (3+ years) or from graduate research. - Direct experience measuring RIN and laser phase or frequency noise, and understanding what limits each measurement (shot noise, thermal noise, instrument floors). - Experience characterizing high-speed pulsed or modulated optical signals: fast photodetectors, sampling oscilloscopes, autocorrelation, optical spectrum analysis. - RF and microwave experience to tens of GHz: phase noise analyzers or signal source analyzers, spectrum analyzers, synthesizers, RF amplifiers, coaxial interconnects. - Comfort with polarization-maintaining fiber: fusion splicing, connector care, PER measurement. - Working knowledge of fiber amplifiers (EDFA). - Python or similar for instrument control and data analysis. - Clear written communication: test procedures, reports, and specs others can act on. PREFERRED SKILLS - Femtosecond-level timing-jitter metrology: photodetected pulse trains, residual phase noise, cross-correlation analyzers. - Experience with mode-locked lasers or electro-optic pulse carving (Mach-Zehnder or thin-film lithium niobate modulators, bias control, RZ formats). - Balanced detection and common-mode rejection measurements. - Stimulated Brillouin scattering, interferometric noise from reflections, and their mitigation. - High-power fiber amplifiers, including multicore or cladding-pumped designs. - Background in optical communications or microwave photonics (coherent or high-baud-rate links, optoelectronic oscillators). - Experience bringing up a new lab and managing equipment purchase or rental. WHAT WE OFFER This is an opportunity to play a pivotal role in an innovative startup redefining the future of AI hardware. Work on game-changing technology at the intersection of photonics and AI as part of a collaborative, brilliant team. You’ll contribute to a platform that redefines computational performance and accelerates the future of artificial intelligence. Come help us bring this transformative technology to the world.   BENEFITS Join a team that invests in your future and your well-being. At Neurophos, we offer: - 100% coverage of base health plan premiums for you and your dependents, plus HSA contributions. - Unlimited PTO. No rigid vacation banks, just a focus on delivery. - 401(k) matching and stock option opportunities to ensure our success is your success. - Full suite of voluntary benefits, including Dental, Vision, Life, Hospital, Critical Illness, and Accident insurance. - Personalized Benefits. Choose the plans that fit your life and take the cash back for those that don’t.