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 Laser System Architecture & Engineering (LSAE) team is seeking a Photonics Circuit Design Engineer. The candidate will design and model the photonic and analog sub-circuits that make up Lightmatter's Guide™ laser products and Passage™ optical links. Examples include the laser source and wavelength-locking blocks, ring filter and modulator banks, mux/demux, optical power splitting and monitoring, and the photodetector-receiver front end.
You will own the bridge between device physics and sub-circuit behavior. You will build high-fidelity behavioral models that capture fabrication variability, dispersion and thermal effects. From them you will assemble sub-circuit models that accurately predict how each block performs. Systems architects will build their end-to-end product simulations on your models, so your models must be accurate, correlated to silicon, and ready to plug into larger simulations.
Responsibilities- Construct and maintain high-fidelity compact and behavioral representations for both active and passive silicon photonic elements, covering waveguides, couplers, MZIs, micro-rings, multiplexers, phase control elements, thermal tuners, modulators, detectors, and integrated III-V/SOA components.
- Incorporate process variations (waveguide geometry and etch biases), dispersion metrics, thermal-optical tuning characteristics, and non-linear properties directly into component modeling.
- Partner with device engineers to extract and calibrate parameter sets using optical solvers (FDTD, EME), foundry process design kits, and physical silicon data across various tapeouts to ensure high model correlation.
- Architect and deliver comprehensive sub-circuit simulations for Guide laser modules, encompassing optical sources, gain media, wavelength control loops, power distribution trees, monitors, and associated analog interfaces (TIAs, converters).
- Implement integrated sub-circuit models for Passage interconnect blocks, including modulated ring arrays, filter banks, thermal controls, drive circuits, DWDM MUX/DEMUX structures, and receiver front-ends.
- Refine sub-circuit topologies against core key performance indicators such as insertion loss, extinction ratio, signal isolation, tuning efficiency, operating bandwidth, and noise performance in collaboration with circuit and device teams.
- Execute corner, statistical Monte Carlo, and margin analyses to establish component tolerances, evaluate yield metrics, and inform experimental test vehicle vehicles and architecture reviews.
- Validate and iterate sub-circuit behavioral representations based on empirical silicon measurements across production cycles.
- Ph.D. in Electrical Engineering, Applied Physics, Photonics, or related discipline plus 2+ years of industry experience (or M.S. with 5+ years). Staff level targeting Ph.D. with 6+ years or M.S. with 10+ years.
- Deep background in silicon photonic physics and analog circuit fundamentals, with proven capability in generating behavioral component models for circuit-level co-simulation.
- Practical expertise using photonic modeling platforms (Lumerical, RSoft, Tidy3D) and analog IC suites (Cadence Virtuoso/Spectre).
- Strong Python software skills for modeling, data extraction, and maintainability of shared engineering codebases.
- Analytical mindset capable of addressing complex, unstructured technical issues through data-driven decisions.
- Methodical approach to engineering, with an emphasis on structured review processes and simulation automation.
- Clear written and verbal technical presentation capabilities.
- Experience with microring modulators and filters, DWDM MUX/DEMUX, and thermal tuning.
- Laser and III-V photonics: DFB, external-cavity or comb sources, SOAs, wavelength lockers, and heterogeneous integration.
- Analog front-end experience with TIAs, modulator drivers, and heater drivers or DACs as they interface to photonic devices.
- Experience with foundry silicon photonics PDKs and process variation data (for example GlobalFoundries, TSMC, Tower, AIM or imec).
- Lab experience correlating models to measurement: OSA, tunable lasers, OVA/LCA, VNA, and wafer-level testing.
- Publications or patents in photonic circuit design or modeling.
We offer competitive compensation. The base salary range for this role determined based on location, experience, educational background, and market data.
- 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.
Skills Required
- Ph.D. in Electrical Engineering, Applied Physics, Photonics, or a related discipline plus 2+ years of industry experience
- Alternatively, an M.S. degree in a related discipline plus 5+ years of industry experience
- Deep knowledge of silicon photonic physics and analog circuit fundamentals
- Experience generating behavioral component models for circuit-level co-simulation
- Practical expertise with Lumerical, RSoft, or Tidy3D
- Practical expertise with Cadence Virtuoso and Spectre
- Strong Python programming skills for modeling and data extraction
- Ability to address complex technical problems using data-driven decisions
- Methodical engineering approach emphasizing structured reviews and simulation automation
- Clear written and verbal technical communication skills
- Experience with microring modulators, filters, DWDM MUX/DEMUX, and thermal tuning
- Experience with DFB lasers, external-cavity or comb sources, SOAs, wavelength lockers, or heterogeneous integration
- Analog front-end experience with TIAs, modulator drivers, heater drivers, or DACs
- Experience with foundry silicon photonics PDKs and process variation data
- Laboratory experience correlating models with measurements using OSA, tunable lasers, OVA/LCA, VNA, or wafer-level testing
- Publications or patents in photonic circuit design or modeling
Lightmatter Compensation & Benefits Highlights
The following summarizes recurring compensation and benefits themes identified from responses generated by popular LLMs to common candidate questions about Lightmatter and has not been reviewed or approved by Lightmatter.
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Fair & Transparent Compensation — Pay is considered competitive for specialized photonics and AI‑hardware roles, with posted ranges and third‑party totals aligning to strong market levels. Compensation for niche roles is framed as consistent with top‑tier hardware/photonics expectations.
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Healthcare Strength — Healthcare is described as comprehensive, covering medical, dental, and vision in current postings. Additional protections like life insurance and disability are also called out.
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Equity Value & Accessibility — Equity grants for full‑time employees are commonly included alongside base pay. Some postings also mention performance‑based equity components.
Lightmatter Insights
What We Do
Lightmatter is a startup photonics company that has pioneered a new paradigm in processor chip architecture that uses photons instead of electrons. Now the leader in the photonic AI compute “space race,” this new class of high performance semiconductors is the foundation of Lightmatter’s mission to enable the growth of computing, reduce harmful emissions associated with this growth, and democratize computing for all. Lightmatter's technology accelerates critical operations in deep neural networks, using an array of programmable photonic elements fabricated alongside transistors in conventional computer chip fabrication processes. Our close-knit team of engineers has created an integrated photonics chip and ultra-high performance interconnect that is faster, more efficient, and cooler than anything else on earth (or anything ever experienced before) to power the next giant leaps in human progress.
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