---
title: 'Principal Field Application Engineer at Lightmatter'
canonical: 'https://feeny.ai/job/principal-field-application-engineer-lightmatter-mountain-view-4s0cgx1wcpe0'
type: 'job'
last_seen: '2026-09-11'
---

# Principal Field Application Engineer at Lightmatter

- **Company:** Lightmatter
- **Location:** Mountain View, CA
- **Compensation:** $250k–$300k
- **Work type:** remote
- **Posted:** 2026-08-12
- **Last confirmed live:** 2026-09-11
- **Apply:** https://boards.greenhouse.io/lightmatter/jobs/5386629008?gh_jid=5386629008

## 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 now looking for an outstanding Field Application Engineer - High-speed I/O Specialist to join our team. The role’s primary responsibility is to work collaboratively with customers in architecting the next generation of devices enabled by Lightmatter’s photonic interconnect technology Passage. In this role, you will work closely with Tier 1 Semiconductor companies that are defining the next generation of silicon in the data center. You will be working cross functionally within Lightmatter as you define an optimal technical solution. Additionally, you will be collaborating with customers who are domain experts in high-speed serial links (SerDes) and protocols. You should be comfortable supporting deep technical discussions focused on high-speed serial I/O design. Excellent interpersonal skills and the ability to work independently are essential to being successful in the role.

## Responsibilities

- Provide the full technical support of the customer HSIO design, including the early technical assessment, design scheme discussion, hardware design review, hardware debug support and other critical trouble shootings
- Develop and deliver technical proposals to customers, based on customer’s technical requirements and system architecture
- Work as the field expert on HSIO area, to provide the in-depth training and guidance of the HSIO design to the FAE team, to create and share the related technical articles and reference designs
- Work collaboratively with Lightmatter Engineering in supporting customer design wins and communicating progress updates to customer engineering leads

## Requirements

- BS or MS in Engineering, Mathematics, Physics, or Computer Science (or equivalent experience).
- 10+ years of work related experience in a high-tech electronics industry with high-speed serial I/O design, including transceiver architecture, CDR, DFE or other
- In-depth knowledge of the signal integrity, power integrity simulation and the related hardware design. Be familiar with the SI/PI EDA simulation tools and models, eg. Keysight ADS.
- Customer facing skill-set and background as well as the ability to communicate effectively with customers
- Action-oriented with strong analytical and problem-solving skills
- Previous experience developing and delivering technical presentations to both executive management and cross-functional engineering teams and external clients
- Built trusted working relationships across teams, improving coordination and execution speed
- Experience working with silicon photonics and/or optical transceiver
- In-depth knowledge of semiconductor and laser technology

## Preferred Qualifications

- Familiar with the digital signal processing theory and the related tools, like Matlab Simulink.
- Analog signal and mixed signal design, ADC, DAC design experience
- C, C++ and other software experience
- Experience working in customer facing role acting as the domain expert for silicon photonics/optics
- Experience deploying or supporting customers who are deploying optics in a data center environment at scale

We offer competitive compensation. On target earnings range is listed below. The final compensation will be determined based on location, experience, educational background, and market data.

Sales Compensation $250,000—$300,000 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
- [Sr Staff/Principal Laser Design Engineer](https://feeny.ai/job/sr-staff-principal-laser-design-engineer-lightmatter-boston-kb2s272z0dqa) — Boston, MA / Mountain View, CA
- [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
- [Staff /Sr Staff Laser Module & Systems Characterization Engineer](https://feeny.ai/job/staff-sr-staff-laser-module-systems-characterization-engineer-lightmatter-1wcg5m40jtae) — Mountain View, CA
- [Package Layout Engineer](https://feeny.ai/job/package-layout-engineer-lightmatter-mountain-view-7jbh4w7py93p) — Mountain View, CA
- [Signal Integrity Engineer](https://feeny.ai/job/signal-integrity-engineer-lightmatter-mountain-view-ayx6663v9ev9) — Mountain View, CA