Optical Engineer - Optical Interconnects

CScale is building the interconnect for gigawatt-scale AI. As AI scale-up moves toward deployments spanning thousands of accelerators and dozens of racks, the network needs to deliver high bandwidth, predictable low latency, and continuous communication. CScale is building integrated optical interconnect designed for this new scale, enabling accelerators to work together like a single, much larger computer. But at this scale, performance is only part of the challenge.

Optical failures are inevitable, and the system needs to keep running. CScale is designing the interconnect for continuity.
Lasers will fail. Compute shouldn’t.The ambition is simple:
Build AI interconnect you can take for granted.CScale came out of stealth in September 2026 with $145 million in Series C funding, bringing total funding to $188 million.

We are seeking an Optical Engineer to take technical ownership of optical subsystems connecting lasers, photonic integrated circuits (PICs), and fiber arrays, with a focus on free-space optical coupling. You will drive development from requirements and architecture through optical design, integration, validation, qualification, and high-volume manufacturing.

This role offers broad scope across the optical system. You will define / improve optical architectures and performance budgets, evaluate design trade-offs, shape component and interface requirements, and lead the integration and validation of complete optical subsystems. Working closely with laser, PIC, electrical, mechanical, thermal, packaging, test, and manufacturing teams, you will contribute to broader product architecture and translate system requirements into practical, production-ready designs.

This is a hands‑on role in a startup environment. You will move between modeling, laboratory development, packaging and alignment work, supplier engagement, and production problem‑solving. Your responsibility extends through manufacturing ramp, with success measured by optical performance, reliability, manufacturing yield, throughput, and cost at volume.

• Own the optical subsystem architecture across laser delivery, PIC coupling, free-space optical elements, and fiber-array interfaces. Evaluate architecture alternatives and contribute to product-level decisions affecting performance, integration, and scalability.
• Translate product requirements into design target, manufacturing spec, interface definitions, and operating margins. Address coupling efficiency, polarization, wavelength dependence, reflections and optical feedback, channel uniformity, crosstalk, and thermal stability as applicable.
• Lead design trade‑offs across optical performance, size, thermal behavior, alignment tolerance, reliability, assembly complexity, production throughput, and cost. Document decisions and validate the assumptions behind them.
• Work with laser and PIC designers, and packaging engineers to define source characteristics, optical modes, coupling structures, channel geometry, and interface requirements that support the overall optical architecture.
• Work with global team extending into 4 different time zones as a joint effort driving forward product development.

• Build, align, characterize, and debug prototypes and integrated optical assemblies. Lead investigation of performance limitations across the complete optical path.
• Collaborate with mechanical, thermal, and packaging engineers on optical datums, component placement, alignment strategies, attachment methods, and assembly sequences. Address bonding‑induced shifts, thermomechanical drift, stress, and contamination risks.
• Own optical verification plans,…