Principal Engineer Jobs in Milpitas, CA

INTRODUCTION

PsiQuantum's mission is to build the first useful quantum computers—machines capable of delivering the breakthroughs the field has long promised. Since our founding in 2016, our singular focus has been to build and deploy million-qubit, fault-tolerant quantum systems.

Quantum computers harness the laws of quantum mechanics to solve problems that even the most advanced supercomputers or AI systems will never reach. Their impact will span energy, pharmaceuticals, finance, agriculture, transportation, materials, and other foundational industries.

Our architecture and approach is based on silicon photonics. By leveraging the advanced semiconductor manufacturing industry—including partners like GlobalFoundries—we use the same high-volume processes that already produce billions of chips for telecom and consumer electronics. Photonics offers natural advantages for scale: photons don't feel heat, are immune to electromagnetic interference, and integrate with existing cryogenic cooling and standard fiber-optic infrastructure.

In 2024, PsiQuantum announced government-funded projects to support the build-out of our first utility-scale quantum computers in Brisbane, Australia, and Chicago, Illinois. These initiatives reflect a growing recognition that quantum computing will be strategically and economically defining—and that now is the time to scale.

PsiQuantum also develops the algorithms and software needed to make these systems commercially valuable. Our application, software, and industry teams work directly with leading Fortune 500 companies—including Lockheed Martin, Mercedes-Benz, Boehringer Ingelheim, and Mitsubishi Chemical—to prepare quantum solutions for real-world impact.

Quantum computing is not an extension of classical computing. It represents a fundamental shift—and a path to mastering challenges that cannot be solved any other way. The potential is enormous, and we have a clear path to make it real.

Come join us.

JOB SUMMARY

The Principle Optical Fiber Architect reports into the System Design organization. This role leads the Optical Distribution Network (ODN) design and integration for current and future systems. This includes the design, development, integration and validation of the fiber network and hardware to support the complex fiber network needed in our quantum systems. They will be responsible to bridge component-level fiber link designs and top-level system requirements, ensuring functionality, reliability, and performance.

Responsibilities

• Technical Lead of the fiber distribution network for current and future system designs.
• Define end-to-end system fiber link architecture connecting subsystems, PICs and control systems. Lead designs that can scale from prototypes to large-scale, manufacturable system fiber networks.
• Establish design principles for ultra-low-loss links, length stability, phase and polarization stability.
• Address thermal drift, vibration sensitivity, and mechanical stability across fiber networks.
• Define guidelines for fiber routing, splicing, connectorization, cleanliness, and handling to meet quantum performance thresholds.
• Own, define & develop design requirements and document requirements for system level behaviors.
• Work effectively with cross functional team: quantum architect, electronics, mechanical and thermal teams and assess how to negotiate for tradeoffs and meet requirements.
• Work with vendors and evaluate advanced fiber optic components, and qualify such components for use in quantum computing applications.
• Assess how to push technical boundaries to meet tight optical specs (optical loss and thermal stability).
• Lead build and test prototypes, maintain a BOM.
• Lead validation tests plans & deliver proof of concept to productization, working closely with the system build and validation team.
• Some Python scripting, calling Controls SW APIs / drivers to control lab equipment and proprietary systems.
• Clear communication and cross functional collaboration.

EXPERIENCE/QUALIFICATIONS

• M.S. or PhD in Physics, Optical or Electrical Engineering with 10+ years industry experience.

• 5+ years experience designing, validating and testing fiber networks and fiber optical systems.

• Deep expertise in fiber optics, including loss mechanisms, dispersion, nonlinear effects, polarization, and phase stability.
• Experience designing fiber optic systems, fiber networking and working with advanced splice equipment and optimization, fiber handling and routing.
• Experience working with optical test equipment including power meters, optical backscatter reflectometers (OBR), optical spectrum analyzer (OSA).
• Experience working with instrumentation used in the photonics and/or the electronics industry.
• Experience with software controls in Python.
• Experience developing test methods and optimization, tuning algorithms.
• Experience in product lifecycles, transitioning from R&D to product development.
• Strong organizational skills, excellent communication skills, attention to detail and ability to multitask.
• Strong critical thinking, creative, innovative, analytical, and detail oriented problem-solving skill.
• Ability to lead and work in a fast paced environment & collaborate with cross functional team.

PsiQuantum provides equal employment opportunity for all applicants and employees. PsiQuantum does not unlawfully discriminate on the basis of race, color, religion, sex (including pregnancy, childbirth, or related medical conditions), gender identity, gender expression, national origin, ancestry, citizenship, age, physical or mental disability, military or veteran status, marital status, domestic partner status, sexual orientation, genetic information, or any other basis protected by applicable laws.

Note: PsiQuantum will only reach out to you using an official PsiQuantum email address and will never ask you for bank account information as part of the interview process. Please report any suspicious activity to recruiting@psiquantum.com.

We are not accepting unsolicited resumes from employment agencies.