Principal Silicon Photonics Test Engineer - Fremont, CA, United States
Originally posted 9 September 2026 by the employer.
About the role
This role involves leading the development of die-level silicon photonics test and characterization strategies, from early device characterization through product qualification and manufacturing readiness, with a focus on photonic integrated circuits (PICs).
What you'll do
- Lead the development of die-level silicon photonics test and characterization strategies.
- Architect and develop automated electro-optical and RF test platforms for silicon photonic devices and PICs.
- Develop characterization methodologies for 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.
- Improve test throughput, repeatability, automation, and cost while maintaining measurement accuracy and coverage.
- Lead root-cause investigations for complex electrical, RF, optical, and electro-optical performance issues.
What you'll need
- 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.
- 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.
This role has been open 35 days — slightly above the 28-day median for Silicon Test Engineering roles.
Silicon Test Engineering · DFT Test
|
Open roles in category
542
|
Median days open
28 d
|
Median salary
$172k
|
See the full market breakdown ▾Category comparison, and who else is hiring
| Metric | Coherent Corp | All employers we track in this specialty (542 roles · 76 employers) |
|---|---|---|
| Open roles in this specialty | 3 | 542 |
| Open roles in the wider Silicon Validation & Test family | 11 | 2224 · 112 employers |
| Median days open | 35 d | 28 d (+7 d vs this employer) |
| Median salary (USD postings) | — | $172k |
Who's hiring in this category
- Teradyne · 72 open roles · median 27 d
- Renesas Electronics · 45 open roles · median 22 d
- Infineon Technologies · 41 open roles · median 37 d
- Micron Technology · 27 open roles · median 35 d
- Qualcomm · 27 open roles · median 27 d
- AMD · 25 open roles · median 42 d
How we counted: 542 open Silicon Test Engineering (DFT Test) roles from 76 employers tracked in the SemiconductorJobs index, counted 15 Oct 2026. Specialty figures count only roles carrying this exact specialty label, so an employer's related work in neighbouring specialties is not included there — it is counted in the wider Silicon Validation & Test family row. Figures refresh nightly.