Job Summary: 

We are seeking an experienced and highly skilled Test Engineer with advanced expertise in high-speed electro-optical components. This individual uses hands-on proficiency with 100+ GHz real-time and sampling oscilloscopes, VNAs, and 1 mm GSSG probes to resolve a wide range of issues and develops new methods to solve problems in testing and optimizing high-speed optical and electrical components, aiming to achieve 400Gbps per optical lane transmissions for data center applications. The ideal candidate will have direct experience with broadband AWGs, electro-optic modulator drivers, and evaluation of Mach-Zehnder Modulators (MZMs) or Electro-Absorption Modulators (EAMs), along with a comprehensive understanding of photonic integration platforms such as TFLN, InP, or SiPh. This professional will lead projects independently with minimal guidance and is proactive in determining methods and procedures. This role requires in-person work in the office.

This role supports the scaling of artificial intelligence (AI)/ machine learning (ML) infrastructure by enabling high-bandwidth, energy-efficient optical links—critical for low-power interconnects in inference and training datacenters, and essential as model sizes grow and data parallelism drives the need for scalable next-generation AI performance.

Primary Duties & Responsibilities

Independently designs and executes experiments and performs high-frequency (≥100 GHz) testing of optical and electrical components in an electro-optical lab environment Analyzes and interprets complex test results, resolves a broad range of issues, and optimizes PAM-4/6/8 transmission and receiver-side equalization (FFE/DFE/CTLE/MLSE) performance for high-speed fiber optic transceivers in innovative ways Works on R&D projects to advance high-speed optical communication technologies Develops and refines product development documentation, including design specifications, test protocols, and reports

Education & Experience

Advanced degree (MSc or PhD) in Electrical Engineering, Optical Engineering, Physics, or a related field. 5 years and a Master’s degree; or a PhD with 3 years experience preferred. Highly advantageous for candidates with strong problem-solving capabilities in high speed data communications electro-optical lab testing.

Eye & Jitter Analysis

Experienced in PAM-4/6/8 eye mask testing, jitter decomposition >100 Gbaud, stressed bathtub curves, and S-parameter/time-domain de-embedding.

Component-Level Knowledge

Modulators: EAMs (chirp, bandwidth), MZMs in SiPh (compact), InP (high BW), TFLN (low Vπ, high linearity), and emerging materials (plasmonic/polymer). Drivers/TIAs: ≥100 GHz drivers (flat gain, return loss), TIAs with 100 GHz BW, low input Z, low NF, and high linearity with photodetectors.

Photonic Integration (Preferred)

Familiar with InP, TFLN, and heterogeneous integration (laser/modulator/detector). Skilled in CPO handling, optical interposers, high-speed substrates, and co-design to minimize insertion/transition loss.

Standards & Analysis

Knowledge of IEEE 802.3dj/df, OIF CEI-112G/224G. TDECQ at 112–140 Gbaud with proper EQ, plus SNR, RIN, and optical noise analysis for IM/DD.

System & DSP Modeling (Preferred)

Channel modeling (loss, ISI, group delay); EQ tuning (FFE, DFE, CTLE, MLSE); BER/FEC analysis; DSP emulation of Rx behavior.

Theory & Simulation

Solid grasp of NRZ vs. PAM tradeoffs, modal dispersion, crosstalk, EO effects (Pockels, Franz–Keldysh, carrier). Tools: COMSOL (EO), Lumerical (FDTD), Keysight ADS (electrical/S-param).

Summary

Expert in 100+ GHz lab instrumentation, RF handling, VNA, and probing. Deep knowledge of modulators (MZM, EAM, TFLN), drivers, TIAs, and photonic platforms (InP, TFLN). Strong in jitter/noise analysis, system modeling, and standards compliance for 400G+/lane IM/DD links. Proactive problem-solver with a deep commitment to optimization and innovation in design and testing.

Working Conditions

Work Onsite

Physical Requirements

Standard

Safety Requirements

All employees are required to follow the site EHS procedures and Coherent Corp. Corporate EHS standards.

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.

 If you need assistance or an accommodation due to a disability, you may contact us at talentacquisition@coherent.com.