Senior Photonics Circuit Design Engineer.

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.

Required Qualifications

• 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.

Preferred Qualifications

• 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.