Principal Silicon Photonics Test Engineer

Location: Fremont, CA, United States; Hybrid

Primary Duties & Responsibilities

• Lead the development of die-level silicon photonics test and characterization strategies, from early device characterization through product qualification and manufacturing readiness.
• Architect and develop automated electro-optical and RF test platforms for silicon photonic devices and photonic integrated circuits (PICs).
• Develop characterization methodologies for devices such as modulators, photodetectors, waveguides, couplers, resonators, and other passive and active photonic components.
• Develop RF and high-speed characterization techniques, including S-parameter measurements, frequency response, electro-optical bandwidth, impedance characterization, and high-speed signal integrity measurements.
• Develop test automation, data acquisition, and analysis software using Python and/or other appropriate programming environments.
• Improve test throughput, repeatability, automation, and cost while maintaining measurement accuracy and coverage.
• Analyze characterization datasets to identify performance distributions, process sensitivities, correlations, failure mechanisms, and opportunities for improved device performance and test efficiency.
• Define test structures and characterization requirements in collaboration with the silicon photonics and design team.
• Partner with process integration, wafer fabrication, packaging, reliability, product engineering, and manufacturing teams to correlate die-level measurements with downstream package and system performance.
• Drive design-for-test (DFT) improvements and influence future device and PIC designs based on characterization results and test limitations.
• Lead root-cause investigations for complex electrical, RF, optical, and electro-optical performance issues.
• Serve as a technical mentor and coach for junior and mid-career engineers, helping them develop strong fundamentals in silicon photonics, RF measurement, electro-optical characterization, and test engineering.
• Review test plans, measurement methodologies, automation code, data analysis, and technical conclusions produced by other engineers, providing constructive technical feedback and guidance.
• Delegate technically challenging projects in a way that develops engineering capability while maintaining appropriate technical oversight.

Education & Experience

• Bachelor’s degree or higher in Electrical Engineering, Optical Engineering, Physics, or a related field.
• Minimum of 5 years of hands-on laboratory experience in photonics, semiconductor, or optoelectronic device testing.
• Experience with high-precision probe stations and electrical/RF probing of semiconductor devices.
• Experience with optical alignment with lenses or fibers to semiconductor devices.
• Strong understanding of silicon photonic devices, including modulators, photodetectors, passive optical structures, and optical coupling techniques.
• Experience developing automated laboratory or production test systems using Python or comparable programming languages.
• Strong hands-on experience with RF/microwave measurement techniques, including vector network analyzers, S-parameters, RF probing, calibration, and de-embedding.
• Experience with data plotting and analysis software such as JMP, MATLAB, or python.

Skills

• Strong expertise in RF and microwave test and measurement, including VNAs, S-parameters, RF probing, calibration, de-embedding, transmission lines, and signal integrity.
• Strong working knowledge of optical test equipment, including tunable lasers, optical power meters, optical spectrum analyzers, polarization controllers, optical switches, and fiber alignment systems.
• Proficiency in Python or similar programming languages for test automation, instrument control, data acquisition, analysis, and visualization.
• Strong troubleshooting and root-cause-analysis skills across optical, electrical, RF, mechanical, software, and semiconductor-device domains.
• Demonstrated ability to transfer specialized knowledge and develop documentation, procedures, training materials, and reference methodologies that enable others to work independently.
• Ability to guide engineers through experimental design, measurement setup, debugging, data interpretation, and root-cause analysis rather than simply providing solutions.
• Ability to teach complex RF, photonics, and measurement concepts through both technical explanation and hands-on laboratory coaching.

Working Conditions

• This position is hybrid.
• May require occasional off-site meetings or travel.
• Regular use of a computer and other office equipment is necessary.
• Interaction with team members and external contacts is a regular part of the job.
• May require occasional overtime and flexibility in work hours to accommodate the executive’s needs.

Physical Requirements

• Sitting for extended periods while working on a computer or conducting meetings.
• Use of hands and fingers for typing, writing, and handling documents.
• Occasional lifting of objects or materials up to 20 pounds for administrative tasks.
• Ability to communicate verbally and in writing.
• Mobility within the office environment to attend meetings or interact with colleagues.

Safety Requirements

All employees are required to attend scheduled training, follow the site EHS procedures and Corporate EHS standards. This includes the use of proper protective equipment (PPE) as required by the job responsibilities.

Managers will ensure that all safety and environmental procedures are followed consistently. They will ensure that risk assessments are performed, proper training, work instructions, required PPE is available, and will monitor compliance.

Quality and Environmental Responsibilities

 

Depending on location, this position may be responsible for the execution and maintenance of the ISO 9000, 9001, 14001 and/or other applicable standards that may apply to the relevant roles and responsibilities within the Quality Management System and Environmental Management System.

Culture Commitment

Ensure adherence to company’s values (ICARE) in all aspects of your position at Coherent Corp.:

Integrity – Create an Environment of Trust

Collaboration – Innovate Through the Sharing of Ideas

Accountability – Own the Process and the Outcome

Respect – Recognize the Value in Everyone

Enthusiasm – Find a Sense of Purpose in Work

Coherent Corp. is an equal opportunity/affirmative action employer. All qualified applicants will receive consideration for employment without regard to sex, gender identity, sexual orientation, race, color, religion, national origin, disability, protected Veteran status, age, or any other characteristic protected by law.

About Us

Coherent is a global leader in lasers, engineered materials and networking components. We are a vertically integrated manufacturing company that develops innovative products for diversified applications in the industrial, optical communications, military, life sciences, semiconductor equipment, and consumer markets. Coherent provides a comprehensive career development platform within an environment that challenges employees to perform at their best, while rewarding excellence and hard-work through a competitive compensation program. It's an exciting opportunity to work for a company that offers stability, longevity and growth. Come Join Us!

Note to recruiters and employment agencies: We will not pay for unsolicited resumes from recruiters and employment agencies unless we have a signed agreement and have required assistance, in writing, for a specific opening.


Job Summary: We are seeking a Principal Silicon Photonics Test Engineer to lead the development and implementation of advanced die-level test and characterization solutions for silicon photonic devices and integrated photonic circuits. This role requires deep expertise in silicon photonics, RF/microwave measurement, and electro-optical device characterization, with a strong emphasis on die-level testing. The successful candidate will define test strategies, develop automated test platforms, establish measurement methodologies, and work closely with design, process, packaging, product, and manufacturing teams to characterize device performance and enable robust, scalable test solutions. As a Principal Engineer, you will serve as a technical leader in silicon photonics test, solving complex measurement challenges and establishing best practices for next-generation photonic products. A critical component of this Principal Engineer role is technical leadership and development of the engine