---
title: 'Senior Laser & SOA Characterization Engineer at Lightmatter'
canonical: 'https://feeny.ai/job/senior-laser-soa-characterization-engineer-lightmatter-mountain-view-sjna8rq0dgvx'
type: 'job'
last_seen: '2026-09-11'
---

# Senior Laser & SOA Characterization Engineer at Lightmatter

- **Company:** Lightmatter
- **Location:** Mountain View, CA
- **Compensation:** $210k–$267k
- **Posted:** 2026-07-02
- **Last confirmed live:** 2026-09-11
- **Apply:** https://boards.greenhouse.io/lightmatter/jobs/5287958008?gh_jid=5287958008

## Job description

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!

## About this Role

We are hiring a senior engineer for our Photonics Characterization team at Lightmatter. Lightmatter is redefining computing by building photonic systems that use light to enable high-bandwidth, energy-efficient AI computing.

In this role, you will lead advanced characterization, bring-up, validation, and root-cause analysis of semiconductor lasers, tunable laser sources, DFB lasers, external-cavity lasers, laser diodes, and semiconductor optical amplifiers. This role requires strong hands-on lab expertise, deep understanding of laser physics and semiconductor device behavior, and the ability to connect measured device performance to design, packaging, system, and reliability implications.

You will own complex optical and electro-optical test setups, develop robust measurement methodologies, automate characterization flows, analyze large datasets, and translate results into clear engineering conclusions. You will also work closely with laser design, photonics, packaging, systems, reliability, and software teams to guide device development from early engineering samples through production-oriented validation.

## Responsibilities

- Lead hands-on characterization of semiconductor lasers, tunable laser sources, DFB lasers, DBR/ECL lasers, laser diodes, and semiconductor optical amplifiers.
- Measure and analyze key laser and SOA performance metrics, including output power, wavelength, optical spectrum, SMSR, RIN, linewidth, gain, saturation power, ASE, noise figure, tuning behavior, optical stability, wavelength stability, and thermal sensitivity.
- Develop advanced LIV, L-I-V-T, wavelength tuning, power stability, RIN, SMSR, linewidth, and long-term drift measurement methodologies.
- Characterize devices across current, voltage, temperature, optical loading, polarization, optical feedback, aging, and operating conditions.
- Analyze SOA gain, gain saturation, wavelength-dependent gain, polarization-dependent gain, ASE noise, carrier dynamics, thermal behavior, and nonlinear effects.
- Build, validate, and maintain automated optical and RF measurement setups using Python, PyVISA, LabVIEW, MATLAB, or similar tools.
- Use modeling and design-analysis software to support characterization planning and data interpretation, including tools for laser physics, optical gain, rate-equation analysis, thermal modeling, optical spectrum analysis, and system-level performance estimation.
- Develop scripts and software workflows for instrument control, automated data collection, calibration, data processing, visualization, statistical analysis, and automated reporting.
- Debug complex optical, electrical, RF, and thermal measurement issues, including optical coupling, polarization sensitivity, back-reflection, RF noise, grounding, calibration error, thermal drift, and instrument limitations.
- Define measurement best practices, calibration procedures, data quality checks, and test documentation standards.
- Translate characterization results into actionable feedback for laser design, photonics integration, packaging, system architecture, and reliability teams.
- Support device bring-up from early engineering samples through mature validation and production-readiness phases.
- Mentor junior engineers and help establish high-quality characterization practices across the team.
- Prepare clear technical reports, design reviews, data summaries, and recommendations for cross-functional engineering teams.

## Qualifications

- PhD or Master’s degree in Electrical Engineering, Physics, Applied Physics, Photonics, Optics, or a related technical field.
- 5+ years of hands-on experience in semiconductor laser, SOA, photonics, or optical device characterization.
- Strong understanding of semiconductor laser physics, optical gain, carrier dynamics, rate equations, thermal effects, feedback sensitivity, linewidth, RIN, and optical noise mechanisms.
- Deep hands-on experience with optical and electro-optical lab measurements.
- Strong familiarity with laser characterization metrics such as threshold current, slope efficiency, wall-plug efficiency, LIV curves, SMSR, RIN, linewidth, wavelength tuning, optical spectrum, power stability, and wavelength stability.
- Strong understanding of semiconductor optical amplifiers, including gain, saturation behavior, ASE, noise, carrier dynamics, polarization dependence, wavelength dependence, and thermal effects.
- Experience operating optical and RF instruments, including laser current drivers, TEC controllers, OSAs, optical power meters, photodetectors, RF spectrum analyzers, oscilloscopes, bias tees, optical filters, polarization controllers, optical switches, and fiber-coupled components.
- Strong Python programming experience for instrument automation, data analysis, plotting, statistical analysis, and automated reporting.
- Experience using software tools for device design support, modeling, simulation, or data-driven analysis.
- Strong analytical skills and ability to debug open-ended device, setup, and measurement problems independently.
- Ability to communicate complex technical results clearly and drive conclusions across design, characterization, packaging, and systems teams.

## Preferred Qualifications

- PhD in Electrical Engineering, Physics, Applied Physics, Photonics, Optics, or a related field.
- Prior experience characterizing DFB lasers, DBR lasers, tunable lasers, ECLs, laser diodes, or SOAs for integrated photonics or optical communication systems.
- Experience with advanced laser-noise measurements, including RIN, linewidth, phase noise, frequency noise, optical feedback sensitivity, and relaxation oscillation analysis.
- Familiarity with laser and SOA modeling, including rate-equation modeling, gain modeling, thermal modeling, optical feedback analysis, and wavelength tuning behavior.
- Experience using commercial or internal simulation/design tools for photonic device analysis, laser design support, or system-level optical performance modeling.
- Experience with III-V semiconductor materials, heterogeneous integration, laser packaging, fiber coupling, optical isolators, and thermal control.
- Experience with high-speed optical or RF measurements involving fast photodetectors, RF spectrum analyzers, oscilloscopes, LNAs, bias tees, and calibration/de-embedding.
- Experience developing automated test platforms for device characterization and validation.
- Experience analyzing large characterization datasets and creating automated dashboards or reports.
- Experience supporting reliability, qualification, or production-oriented validation of semiconductor lasers or optical amplifiers.
- Demonstrated ability to lead technical work independently, define test strategy, mentor junior engineers, and influence cross-functional engineering decisions.

We offer competitive compensation. The base salary range for this role determined based on location, experience, educational background, and market data.

Salary Range: total compensation goes beyond base salary, it also includes a new hire equity grant, annual performance-based equity, and other rewards that recognize your impact and contribution. $210,000—$267,000 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.

## About Lightmatter

## Company Overview
- **One-liner**: Lightmatter builds photonic interconnects and computing infrastructure to eliminate bandwidth bottlenecks in AI and high-performance computing, enabling the next era of AI scaling.
- **Entity Type**: Private (Series D, $850M total funding)
- **Headquarters**: Mountain View, California, USA
- **Founded**: 2017
- **Founders**: Nicholas Harris, PhD (CEO), Darius Bunandar, PhD (Head of Machine Learning), and a third co-founder (Chief Scientist)

## Core Business
- **Primary industry**: Silicon Photonics / AI Infrastructure / Semiconductor
- **Target customers**: Hyperscale data center operators, AI labs (training frontier models), cloud service providers, and enterprise AI teams
- **Mission or purpose**: To make computers keep getting better by using light instead of electricity for data movement, solving the fundamental bandwidth bottleneck that limits AI scaling.

## Products & Services
- **Passage™ Platform**: A family of 3D-stacked silicon photonics interconnects (NPO, OBO, 2D/3D CPO, 3D interposers) that provide "Edgeless I/O"—unlimited bandwidth scaling for AI supercomputers. Key variants include:
  - **Passage M1000 EVK**: Rack-level 3D photonic interposer delivering 114 Tbps across a 4,000 mm² footprint.
  - **Passage L200**: Designed for frontier-scale training, supporting 32–64 Tbps aggregate bandwidth via co-packaged optics (112G PAM4).
  - **Passage L20**: Accelerates optics integration with 12.8 Tbps aggregate bandwidth and 4x pluggable density.
  - **Passage EVK100**: High-bandwidth bidirectional link at 3.2 Tbps per fiber, 1.9 pJ/bit.
  - **Passage EVK50**: 16-wavelength bidirectional link at 800 Gbps per fiber, 2.6 pJ/bit.
- **Guide® Light Engines**: Very Large Scale Photonics technology—a universal light source (hundreds of lasers and photonics components on a single chip) designed to power co-packaged optics across the entire photonics industry.

## Market Standing
- **Valuation**: $4.4 billion (as of October 2024)
- **Key Metric**: $850M total funding raised
- **Notable Investors/Partners**: TSMC, GlobalFoundries, Tower Semiconductor (manufacturing partners); Amkor, ASE (packaging partners); NVIDIA (joined NVLink Fusion ecosystem); standards bodies including Ultra Ethernet, UALink, JEDEC, OIF, IEEE, OCP, and the Advanced Photonics Coalition.
- **Growth Signals**: First-mover in category-defining photonic interconnects; multiple generations of production-ready technology (not vaporware); reference platforms in customer hands; 100,000+ GPU cluster capability; world-first 16-wavelength bidirectional optical DWDM link on standard single-mode fiber (8x leap in bandwidth density); partnerships with top foundries ensure high-volume manufacturing.

## Competitive Advantages
- **Edgeless I/O architecture**: Eliminates the physical chip-perimeter constraint that limits electrical interconnects, enabling bandwidth to scale without bound.
- **Fundamentally better physics**: Photons travel without resistive loss, cross paths without interference, and carry multiple signals on a single fiber—far more efficient than electrons.
- **Deep vertical integration**: From photonic chip design to light engines (Guide) to complete interconnect platforms (Passage), with proprietary 3D stacking technology.
- **Decade-scale roadmap**: Continued bandwidth scaling (114 Tbps today, 1+ Pbps tomorrow) with production-ready silicon validated at scale.
- **Ecosystem lock-in**: Standards body leadership and partnerships with NVIDIA, TSMC, and hyperscalers create high switching costs.

## Strategic Focus
- **Scale AI infrastructure**: Enable 100,000+ GPU clusters for trillion-parameter models, solving the interconnect bottleneck that currently strands hundreds of millions in compute capacity.
- **Productize photonics**: Move from reference platforms to volume production across Passage and Guide families, targeting both training and inference workloads.
- **Expand ecosystem**: Deepen partnerships with hyperscalers, AI labs, and chipmakers (e.g., NVIDIA NVLink Fusion) to make photonic interconnects the default for next-gen data centers.
- **Hire across all functions**: Actively growing engineering, research, sales, and operations teams to scale the company.

## Why Work Here
- **Mission-driven impact**: Work at the intersection of photonics, AI, and semiconductor engineering to solve the most critical bottleneck in AI—data movement. Your work directly enables frontier models and trillion-parameter training.
- **World-class team**: Colleagues from MIT, Caltech, Stanford, and UC Berkeley; published in Nature, Science, ISSCC, ISCA; 100+ patents; team members contributed to black hole simulation software for the Academy Award-winning movie *Interstellar*.
- **Cutting-edge technology**: Not research, not vaporware—multiple generations of production-ready photonic chips in customer hands, with a decade-scale roadmap.
- **Locations**: Mountain View, CA (HQ); Boston, MA; Hsinchu, Taiwan; Toronto, Canada.
- **Benefits**: 401(k), generous vacation policy and holidays, commuter benefits, happy hours, and a strong learning culture (peer-to-peer knowledge sharing across electronics, photonics, machine learning, and more).
- **Culture**: "We are one Lightmatter"—collaborative, cross-disciplinary, and focused on solving hard problems at scale.

## Sources
1. [lightmatter.co/about](https://lightmatter.co/about/)
2. [lightmatter.co](https://lightmatter.co/)
3. [lightmatter.co/people/careers](https://lightmatter.co/people/careers/)
4. [lightmatter.co/people](https://lightmatter.co/people/)
5. [linkedin.com/company/lightmatter](https://www.linkedin.com/company/lightmatter)

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