---
title: 'Sr Staff/Principal Laser Design Engineer at Lightmatter'
canonical: 'https://feeny.ai/job/sr-staff-principal-laser-design-engineer-lightmatter-boston-kb2s272z0dqa'
type: 'job'
last_seen: '2026-09-11'
---

# Sr Staff/Principal Laser Design Engineer at Lightmatter

- **Company:** Lightmatter
- **Location:** Boston, MA / Mountain View, CA
- **Compensation:** $212k–$320k
- **Posted:** 2026-09-11
- **Last confirmed live:** 2026-09-11
- **Apply:** https://boards.greenhouse.io/lightmatter/jobs/5407374008?gh_jid=5407374008

## 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!

We are hiring a Laser Design Engineer to join our laser module development team. In this role, you will own the design of high-power laser epitaxy and laser devices—including DFB, DBR, and external-cavity architectures—for Lightmatter’s integrated and highly scalable laser solutions for AI communications and computation. You will drive designs from epitaxial layer stack through cavity and device architecture, working closely with colleagues and cross-disciplinary engineering teams internally and across our ecosystem of manufacturing partners to translate system requirements into robust, manufacturable, high-reliability hardware.

This role requires deep expertise in semiconductor laser and epitaxy design, a strong command of laser and semiconductor device physics, and the judgment to navigate the design space of performance, schedule, reliability, power consumption, and cost. As a senior technical anchor, you will plan and execute across multiple concurrent programs, resolve critical and often ambiguous technical challenges with limited oversight, develop new methods and design approaches, and serve as a recognized internal subject-matter expert. Creativity, analytical rigor, and clear communication are essential.

Join a tight-knit team where each individual’s contributions directly influence the success of the company and product. You’ll have the opportunity to build innovative laser solutions from the ground up and tackle groundbreaking challenges. Work with people who love to build and who thrive in diverse technical environments where great ideas are prioritized.

## Responsibilities

- Own the design of high-power laser epitaxial structures and laser devices—including DFB, DBR, and external-cavity architectures.
- Design epitaxial layer stacks in III-V material systems, optimizing for optical gain, carrier confinement, threshold current density, wall-plug efficiency, and high-temperature performance.
- Optimize laser cavity designs to achieve target output power, precise wavelength control, narrow linewidth, high side-mode suppression ratio (SMSR), low relative intensity noise (RIN), and robust back-reflection tolerance.
- Contribute to monolithic and silicon-photonics heterogeneously integrated laser and semiconductor optical amplifier (SOA) development.
- Use physics-based and traveling-wave simulation tools to model heterostructure and cavity behavior, spectral response, and tuning, translating high-level system needs into detailed device designs.
- Partner with the characterization team to define test beds and map measured L-I-V curves, near-/far-field profiles, thermal coefficients, and linewidth back to design parameters, iterating to close performance gaps.
- Collaborate across disciplines—systems, analog/electrical, packaging, and thermal engineering—to define component-level specs derived from link budgets, co-design drivers and submounts, and define optical coupling and thermal-management strategies.
- Work with epitaxy and foundry vendors to specify, qualify, and transfer designs into volume manufacturing.
- Act as an internal subject-matter expert and thought leader on laser device and epi design; mentor engineers, review designs, and contribute to the laser technology roadmap for performance, scalability, power, and cost.
- Publish and present novel ideas, and participate in premier photonics conferences.

## Requirements

- A Ph.D. in Photonics, Electrical Engineering, Applied Physics, Materials Science, or a related discipline with at least 5 years of relevant post-degree experience; or an M.S. with at least 8 years of relevant experience; or equivalent experience.
- Deep, hands-on expertise in semiconductor laser and epitaxy design for III-V compound semiconductor devices.
- Proven track record designing DFB, DBR, and/or external-cavity lasers.
- Strong grounding in laser physics and semiconductor device physics (optical gain, threshold, slope efficiency, RIN, linewidth, thermal rollover, and back-reflection behavior).
- Proficiency with physics-based laser and photonic device simulation tools (e.g., PhotonDesign Harold/PICWave, VPIphotonics, Lumerical, or equivalent) and data analysis in Python.
- Demonstrated ability to independently own complex designs spanning multiple programs, and to resolve critical, ambiguous technical issues as a recognized subject-matter expert.
- Track record of close collaboration with characterization/test teams and cross-functional hardware teams.
- Ability to convey complex technical concepts to both technical and non-technical stakeholders with strong and clear communication.

## Preferred Qualifications

- Experience with silicon photonics and heterogeneous integration of III-V gain material on silicon.
- Experience designing semiconductor optical amplifiers (SOAs).
- Experience with high power semiconductor lasers for datacom applications.
- Experience maturing a laser product from prototype through high-volume manufacturing, including epi growth and reliability qualification.
- A record of publishing novel photonics results and engaging with the broader optics community.
- Willing and able to learn quickly, self-starter with a “no task is too big or small” attitude.

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. $212,000—$320,000 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)

## Other roles at Lightmatter

- [Sr Staff/Principal Laser Design Engineer](https://feeny.ai/job/sr-staff-principal-laser-design-engineer-lightmatter-toronto-ggzwe7cse995) — Toronto, Canada
- [Photonics Characterization Intern & New Grad](https://feeny.ai/job/photonics-characterization-intern-new-grad-lightmatter-boston-ctktrnqyp6j3) — Boston, MA
- [Electro-Optic Link Hardware Engineer](https://feeny.ai/job/electro-optic-link-hardware-engineer-lightmatter-boston-datxb52a2c2k) — Boston, MA / Mountain View, CA
- [Principal Hardware Systems Technical Lead](https://feeny.ai/job/principal-hardware-systems-technical-lead-lightmatter-mountain-view-s2s15x7ed12e) — Mountain View, CA
- [Staff/Sr Staff Electro-Optic Link Codesign Engineer](https://feeny.ai/job/staff-sr-staff-electro-optic-link-codesign-engineer-lightmatter-boston-4ddybajp6gbf) — Boston, MA / Mountain View, CA / Toronto, Canada
- [Senior Account Manager](https://feeny.ai/job/senior-account-manager-lightmatter-mountain-view-zcefyvftztp2) — Mountain View, CA
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